Merge #9911: Wshadow: various gcc fixes
[bitcoinplatinum.git] / src / tinyformat.h
blob5022d4680911452966597483cc916b1b5454950a
1 // tinyformat.h
2 // Copyright (C) 2011, Chris Foster [chris42f (at) gmail (d0t) com]
3 //
4 // Boost Software License - Version 1.0
5 //
6 // Permission is hereby granted, free of charge, to any person or organization
7 // obtaining a copy of the software and accompanying documentation covered by
8 // this license (the "Software") to use, reproduce, display, distribute,
9 // execute, and transmit the Software, and to prepare derivative works of the
10 // Software, and to permit third-parties to whom the Software is furnished to
11 // do so, all subject to the following:
13 // The copyright notices in the Software and this entire statement, including
14 // the above license grant, this restriction and the following disclaimer,
15 // must be included in all copies of the Software, in whole or in part, and
16 // all derivative works of the Software, unless such copies or derivative
17 // works are solely in the form of machine-executable object code generated by
18 // a source language processor.
20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
23 // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
24 // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
25 // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
26 // DEALINGS IN THE SOFTWARE.
28 //------------------------------------------------------------------------------
29 // Tinyformat: A minimal type safe printf replacement
31 // tinyformat.h is a type safe printf replacement library in a single C++
32 // header file. Design goals include:
34 // * Type safety and extensibility for user defined types.
35 // * C99 printf() compatibility, to the extent possible using std::ostream
36 // * Simplicity and minimalism. A single header file to include and distribute
37 // with your projects.
38 // * Augment rather than replace the standard stream formatting mechanism
39 // * C++98 support, with optional C++11 niceties
42 // Main interface example usage
43 // ----------------------------
45 // To print a date to std::cout:
47 // std::string weekday = "Wednesday";
48 // const char* month = "July";
49 // size_t day = 27;
50 // long hour = 14;
51 // int min = 44;
53 // tfm::printf("%s, %s %d, %.2d:%.2d\n", weekday, month, day, hour, min);
55 // The strange types here emphasize the type safety of the interface; it is
56 // possible to print a std::string using the "%s" conversion, and a
57 // size_t using the "%d" conversion. A similar result could be achieved
58 // using either of the tfm::format() functions. One prints on a user provided
59 // stream:
61 // tfm::format(std::cerr, "%s, %s %d, %.2d:%.2d\n",
62 // weekday, month, day, hour, min);
64 // The other returns a std::string:
66 // std::string date = tfm::format("%s, %s %d, %.2d:%.2d\n",
67 // weekday, month, day, hour, min);
68 // std::cout << date;
70 // These are the three primary interface functions. There is also a
71 // convenience function printfln() which appends a newline to the usual result
72 // of printf() for super simple logging.
75 // User defined format functions
76 // -----------------------------
78 // Simulating variadic templates in C++98 is pretty painful since it requires
79 // writing out the same function for each desired number of arguments. To make
80 // this bearable tinyformat comes with a set of macros which are used
81 // internally to generate the API, but which may also be used in user code.
83 // The three macros TINYFORMAT_ARGTYPES(n), TINYFORMAT_VARARGS(n) and
84 // TINYFORMAT_PASSARGS(n) will generate a list of n argument types,
85 // type/name pairs and argument names respectively when called with an integer
86 // n between 1 and 16. We can use these to define a macro which generates the
87 // desired user defined function with n arguments. To generate all 16 user
88 // defined function bodies, use the macro TINYFORMAT_FOREACH_ARGNUM. For an
89 // example, see the implementation of printf() at the end of the source file.
91 // Sometimes it's useful to be able to pass a list of format arguments through
92 // to a non-template function. The FormatList class is provided as a way to do
93 // this by storing the argument list in a type-opaque way. Continuing the
94 // example from above, we construct a FormatList using makeFormatList():
96 // FormatListRef formatList = tfm::makeFormatList(weekday, month, day, hour, min);
98 // The format list can now be passed into any non-template function and used
99 // via a call to the vformat() function:
101 // tfm::vformat(std::cout, "%s, %s %d, %.2d:%.2d\n", formatList);
104 // Additional API information
105 // --------------------------
107 // Error handling: Define TINYFORMAT_ERROR to customize the error handling for
108 // format strings which are unsupported or have the wrong number of format
109 // specifiers (calls assert() by default).
111 // User defined types: Uses operator<< for user defined types by default.
112 // Overload formatValue() for more control.
115 #ifndef TINYFORMAT_H_INCLUDED
116 #define TINYFORMAT_H_INCLUDED
118 namespace tinyformat {}
119 //------------------------------------------------------------------------------
120 // Config section. Customize to your liking!
122 // Namespace alias to encourage brevity
123 namespace tfm = tinyformat;
125 // Error handling; calls assert() by default.
126 #define TINYFORMAT_ERROR(reasonString) throw tinyformat::format_error(reasonString)
128 // Define for C++11 variadic templates which make the code shorter & more
129 // general. If you don't define this, C++11 support is autodetected below.
130 #define TINYFORMAT_USE_VARIADIC_TEMPLATES
133 //------------------------------------------------------------------------------
134 // Implementation details.
135 #include <algorithm>
136 #include <cassert>
137 #include <iostream>
138 #include <sstream>
139 #include <stdexcept>
141 #ifndef TINYFORMAT_ERROR
142 # define TINYFORMAT_ERROR(reason) assert(0 && reason)
143 #endif
145 #if !defined(TINYFORMAT_USE_VARIADIC_TEMPLATES) && !defined(TINYFORMAT_NO_VARIADIC_TEMPLATES)
146 # ifdef __GXX_EXPERIMENTAL_CXX0X__
147 # define TINYFORMAT_USE_VARIADIC_TEMPLATES
148 # endif
149 #endif
151 #if defined(__GLIBCXX__) && __GLIBCXX__ < 20080201
152 // std::showpos is broken on old libstdc++ as provided with OSX. See
153 // http://gcc.gnu.org/ml/libstdc++/2007-11/msg00075.html
154 # define TINYFORMAT_OLD_LIBSTDCPLUSPLUS_WORKAROUND
155 #endif
157 #ifdef __APPLE__
158 // Workaround OSX linker warning: xcode uses different default symbol
159 // visibilities for static libs vs executables (see issue #25)
160 # define TINYFORMAT_HIDDEN __attribute__((visibility("hidden")))
161 #else
162 # define TINYFORMAT_HIDDEN
163 #endif
165 namespace tinyformat {
167 class format_error: public std::runtime_error
169 public:
170 format_error(const std::string &what): std::runtime_error(what) {
174 //------------------------------------------------------------------------------
175 namespace detail {
177 // Test whether type T1 is convertible to type T2
178 template <typename T1, typename T2>
179 struct is_convertible
181 private:
182 // two types of different size
183 struct fail { char dummy[2]; };
184 struct succeed { char dummy; };
185 // Try to convert a T1 to a T2 by plugging into tryConvert
186 static fail tryConvert(...);
187 static succeed tryConvert(const T2&);
188 static const T1& makeT1();
189 public:
190 # ifdef _MSC_VER
191 // Disable spurious loss of precision warnings in tryConvert(makeT1())
192 # pragma warning(push)
193 # pragma warning(disable:4244)
194 # pragma warning(disable:4267)
195 # endif
196 // Standard trick: the (...) version of tryConvert will be chosen from
197 // the overload set only if the version taking a T2 doesn't match.
198 // Then we compare the sizes of the return types to check which
199 // function matched. Very neat, in a disgusting kind of way :)
200 static const bool value =
201 sizeof(tryConvert(makeT1())) == sizeof(succeed);
202 # ifdef _MSC_VER
203 # pragma warning(pop)
204 # endif
208 // Detect when a type is not a wchar_t string
209 template<typename T> struct is_wchar { typedef int tinyformat_wchar_is_not_supported; };
210 template<> struct is_wchar<wchar_t*> {};
211 template<> struct is_wchar<const wchar_t*> {};
212 template<int n> struct is_wchar<const wchar_t[n]> {};
213 template<int n> struct is_wchar<wchar_t[n]> {};
216 // Format the value by casting to type fmtT. This default implementation
217 // should never be called.
218 template<typename T, typename fmtT, bool convertible = is_convertible<T, fmtT>::value>
219 struct formatValueAsType
221 static void invoke(std::ostream& /*out*/, const T& /*value*/) { assert(0); }
223 // Specialized version for types that can actually be converted to fmtT, as
224 // indicated by the "convertible" template parameter.
225 template<typename T, typename fmtT>
226 struct formatValueAsType<T,fmtT,true>
228 static void invoke(std::ostream& out, const T& value)
229 { out << static_cast<fmtT>(value); }
232 #ifdef TINYFORMAT_OLD_LIBSTDCPLUSPLUS_WORKAROUND
233 template<typename T, bool convertible = is_convertible<T, int>::value>
234 struct formatZeroIntegerWorkaround
236 static bool invoke(std::ostream& /**/, const T& /**/) { return false; }
238 template<typename T>
239 struct formatZeroIntegerWorkaround<T,true>
241 static bool invoke(std::ostream& out, const T& value)
243 if (static_cast<int>(value) == 0 && out.flags() & std::ios::showpos)
245 out << "+0";
246 return true;
248 return false;
251 #endif // TINYFORMAT_OLD_LIBSTDCPLUSPLUS_WORKAROUND
253 // Convert an arbitrary type to integer. The version with convertible=false
254 // throws an error.
255 template<typename T, bool convertible = is_convertible<T,int>::value>
256 struct convertToInt
258 static int invoke(const T& /*value*/)
260 TINYFORMAT_ERROR("tinyformat: Cannot convert from argument type to "
261 "integer for use as variable width or precision");
262 return 0;
265 // Specialization for convertToInt when conversion is possible
266 template<typename T>
267 struct convertToInt<T,true>
269 static int invoke(const T& value) { return static_cast<int>(value); }
272 // Format at most ntrunc characters to the given stream.
273 template<typename T>
274 inline void formatTruncated(std::ostream& out, const T& value, int ntrunc)
276 std::ostringstream tmp;
277 tmp << value;
278 std::string result = tmp.str();
279 out.write(result.c_str(), (std::min)(ntrunc, static_cast<int>(result.size())));
281 #define TINYFORMAT_DEFINE_FORMAT_TRUNCATED_CSTR(type) \
282 inline void formatTruncated(std::ostream& out, type* value, int ntrunc) \
284 std::streamsize len = 0; \
285 while(len < ntrunc && value[len] != 0) \
286 ++len; \
287 out.write(value, len); \
289 // Overload for const char* and char*. Could overload for signed & unsigned
290 // char too, but these are technically unneeded for printf compatibility.
291 TINYFORMAT_DEFINE_FORMAT_TRUNCATED_CSTR(const char)
292 TINYFORMAT_DEFINE_FORMAT_TRUNCATED_CSTR(char)
293 #undef TINYFORMAT_DEFINE_FORMAT_TRUNCATED_CSTR
295 } // namespace detail
298 //------------------------------------------------------------------------------
299 // Variable formatting functions. May be overridden for user-defined types if
300 // desired.
303 /// Format a value into a stream, delegating to operator<< by default.
305 /// Users may override this for their own types. When this function is called,
306 /// the stream flags will have been modified according to the format string.
307 /// The format specification is provided in the range [fmtBegin, fmtEnd). For
308 /// truncating conversions, ntrunc is set to the desired maximum number of
309 /// characters, for example "%.7s" calls formatValue with ntrunc = 7.
311 /// By default, formatValue() uses the usual stream insertion operator
312 /// operator<< to format the type T, with special cases for the %c and %p
313 /// conversions.
314 template<typename T>
315 inline void formatValue(std::ostream& out, const char* /*fmtBegin*/,
316 const char* fmtEnd, int ntrunc, const T& value)
318 #ifndef TINYFORMAT_ALLOW_WCHAR_STRINGS
319 // Since we don't support printing of wchar_t using "%ls", make it fail at
320 // compile time in preference to printing as a void* at runtime.
321 typedef typename detail::is_wchar<T>::tinyformat_wchar_is_not_supported DummyType;
322 (void) DummyType(); // avoid unused type warning with gcc-4.8
323 #endif
324 // The mess here is to support the %c and %p conversions: if these
325 // conversions are active we try to convert the type to a char or const
326 // void* respectively and format that instead of the value itself. For the
327 // %p conversion it's important to avoid dereferencing the pointer, which
328 // could otherwise lead to a crash when printing a dangling (const char*).
329 const bool canConvertToChar = detail::is_convertible<T,char>::value;
330 const bool canConvertToVoidPtr = detail::is_convertible<T, const void*>::value;
331 if(canConvertToChar && *(fmtEnd-1) == 'c')
332 detail::formatValueAsType<T, char>::invoke(out, value);
333 else if(canConvertToVoidPtr && *(fmtEnd-1) == 'p')
334 detail::formatValueAsType<T, const void*>::invoke(out, value);
335 #ifdef TINYFORMAT_OLD_LIBSTDCPLUSPLUS_WORKAROUND
336 else if(detail::formatZeroIntegerWorkaround<T>::invoke(out, value)) /**/;
337 #endif
338 else if(ntrunc >= 0)
340 // Take care not to overread C strings in truncating conversions like
341 // "%.4s" where at most 4 characters may be read.
342 detail::formatTruncated(out, value, ntrunc);
344 else
345 out << value;
349 // Overloaded version for char types to support printing as an integer
350 #define TINYFORMAT_DEFINE_FORMATVALUE_CHAR(charType) \
351 inline void formatValue(std::ostream& out, const char* /*fmtBegin*/, \
352 const char* fmtEnd, int /**/, charType value) \
354 switch(*(fmtEnd-1)) \
356 case 'u': case 'd': case 'i': case 'o': case 'X': case 'x': \
357 out << static_cast<int>(value); break; \
358 default: \
359 out << value; break; \
362 // per 3.9.1: char, signed char and unsigned char are all distinct types
363 TINYFORMAT_DEFINE_FORMATVALUE_CHAR(char)
364 TINYFORMAT_DEFINE_FORMATVALUE_CHAR(signed char)
365 TINYFORMAT_DEFINE_FORMATVALUE_CHAR(unsigned char)
366 #undef TINYFORMAT_DEFINE_FORMATVALUE_CHAR
369 //------------------------------------------------------------------------------
370 // Tools for emulating variadic templates in C++98. The basic idea here is
371 // stolen from the boost preprocessor metaprogramming library and cut down to
372 // be just general enough for what we need.
374 #define TINYFORMAT_ARGTYPES(n) TINYFORMAT_ARGTYPES_ ## n
375 #define TINYFORMAT_VARARGS(n) TINYFORMAT_VARARGS_ ## n
376 #define TINYFORMAT_PASSARGS(n) TINYFORMAT_PASSARGS_ ## n
377 #define TINYFORMAT_PASSARGS_TAIL(n) TINYFORMAT_PASSARGS_TAIL_ ## n
379 // To keep it as transparent as possible, the macros below have been generated
380 // using python via the excellent cog.py code generation script. This avoids
381 // the need for a bunch of complex (but more general) preprocessor tricks as
382 // used in boost.preprocessor.
384 // To rerun the code generation in place, use `cog.py -r tinyformat.h`
385 // (see http://nedbatchelder.com/code/cog). Alternatively you can just create
386 // extra versions by hand.
388 /*[[[cog
389 maxParams = 16
391 def makeCommaSepLists(lineTemplate, elemTemplate, startInd=1):
392 for j in range(startInd,maxParams+1):
393 list = ', '.join([elemTemplate % {'i':i} for i in range(startInd,j+1)])
394 cog.outl(lineTemplate % {'j':j, 'list':list})
396 makeCommaSepLists('#define TINYFORMAT_ARGTYPES_%(j)d %(list)s',
397 'class T%(i)d')
399 cog.outl()
400 makeCommaSepLists('#define TINYFORMAT_VARARGS_%(j)d %(list)s',
401 'const T%(i)d& v%(i)d')
403 cog.outl()
404 makeCommaSepLists('#define TINYFORMAT_PASSARGS_%(j)d %(list)s', 'v%(i)d')
406 cog.outl()
407 cog.outl('#define TINYFORMAT_PASSARGS_TAIL_1')
408 makeCommaSepLists('#define TINYFORMAT_PASSARGS_TAIL_%(j)d , %(list)s',
409 'v%(i)d', startInd = 2)
411 cog.outl()
412 cog.outl('#define TINYFORMAT_FOREACH_ARGNUM(m) \\\n ' +
413 ' '.join(['m(%d)' % (j,) for j in range(1,maxParams+1)]))
414 ]]]*/
415 #define TINYFORMAT_ARGTYPES_1 class T1
416 #define TINYFORMAT_ARGTYPES_2 class T1, class T2
417 #define TINYFORMAT_ARGTYPES_3 class T1, class T2, class T3
418 #define TINYFORMAT_ARGTYPES_4 class T1, class T2, class T3, class T4
419 #define TINYFORMAT_ARGTYPES_5 class T1, class T2, class T3, class T4, class T5
420 #define TINYFORMAT_ARGTYPES_6 class T1, class T2, class T3, class T4, class T5, class T6
421 #define TINYFORMAT_ARGTYPES_7 class T1, class T2, class T3, class T4, class T5, class T6, class T7
422 #define TINYFORMAT_ARGTYPES_8 class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8
423 #define TINYFORMAT_ARGTYPES_9 class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9
424 #define TINYFORMAT_ARGTYPES_10 class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10
425 #define TINYFORMAT_ARGTYPES_11 class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class T11
426 #define TINYFORMAT_ARGTYPES_12 class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class T11, class T12
427 #define TINYFORMAT_ARGTYPES_13 class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class T11, class T12, class T13
428 #define TINYFORMAT_ARGTYPES_14 class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class T11, class T12, class T13, class T14
429 #define TINYFORMAT_ARGTYPES_15 class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class T11, class T12, class T13, class T14, class T15
430 #define TINYFORMAT_ARGTYPES_16 class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class T11, class T12, class T13, class T14, class T15, class T16
432 #define TINYFORMAT_VARARGS_1 const T1& v1
433 #define TINYFORMAT_VARARGS_2 const T1& v1, const T2& v2
434 #define TINYFORMAT_VARARGS_3 const T1& v1, const T2& v2, const T3& v3
435 #define TINYFORMAT_VARARGS_4 const T1& v1, const T2& v2, const T3& v3, const T4& v4
436 #define TINYFORMAT_VARARGS_5 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5
437 #define TINYFORMAT_VARARGS_6 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6
438 #define TINYFORMAT_VARARGS_7 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7
439 #define TINYFORMAT_VARARGS_8 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7, const T8& v8
440 #define TINYFORMAT_VARARGS_9 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7, const T8& v8, const T9& v9
441 #define TINYFORMAT_VARARGS_10 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7, const T8& v8, const T9& v9, const T10& v10
442 #define TINYFORMAT_VARARGS_11 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7, const T8& v8, const T9& v9, const T10& v10, const T11& v11
443 #define TINYFORMAT_VARARGS_12 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7, const T8& v8, const T9& v9, const T10& v10, const T11& v11, const T12& v12
444 #define TINYFORMAT_VARARGS_13 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7, const T8& v8, const T9& v9, const T10& v10, const T11& v11, const T12& v12, const T13& v13
445 #define TINYFORMAT_VARARGS_14 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7, const T8& v8, const T9& v9, const T10& v10, const T11& v11, const T12& v12, const T13& v13, const T14& v14
446 #define TINYFORMAT_VARARGS_15 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7, const T8& v8, const T9& v9, const T10& v10, const T11& v11, const T12& v12, const T13& v13, const T14& v14, const T15& v15
447 #define TINYFORMAT_VARARGS_16 const T1& v1, const T2& v2, const T3& v3, const T4& v4, const T5& v5, const T6& v6, const T7& v7, const T8& v8, const T9& v9, const T10& v10, const T11& v11, const T12& v12, const T13& v13, const T14& v14, const T15& v15, const T16& v16
449 #define TINYFORMAT_PASSARGS_1 v1
450 #define TINYFORMAT_PASSARGS_2 v1, v2
451 #define TINYFORMAT_PASSARGS_3 v1, v2, v3
452 #define TINYFORMAT_PASSARGS_4 v1, v2, v3, v4
453 #define TINYFORMAT_PASSARGS_5 v1, v2, v3, v4, v5
454 #define TINYFORMAT_PASSARGS_6 v1, v2, v3, v4, v5, v6
455 #define TINYFORMAT_PASSARGS_7 v1, v2, v3, v4, v5, v6, v7
456 #define TINYFORMAT_PASSARGS_8 v1, v2, v3, v4, v5, v6, v7, v8
457 #define TINYFORMAT_PASSARGS_9 v1, v2, v3, v4, v5, v6, v7, v8, v9
458 #define TINYFORMAT_PASSARGS_10 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10
459 #define TINYFORMAT_PASSARGS_11 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11
460 #define TINYFORMAT_PASSARGS_12 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12
461 #define TINYFORMAT_PASSARGS_13 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13
462 #define TINYFORMAT_PASSARGS_14 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14
463 #define TINYFORMAT_PASSARGS_15 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15
464 #define TINYFORMAT_PASSARGS_16 v1, v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15, v16
466 #define TINYFORMAT_PASSARGS_TAIL_1
467 #define TINYFORMAT_PASSARGS_TAIL_2 , v2
468 #define TINYFORMAT_PASSARGS_TAIL_3 , v2, v3
469 #define TINYFORMAT_PASSARGS_TAIL_4 , v2, v3, v4
470 #define TINYFORMAT_PASSARGS_TAIL_5 , v2, v3, v4, v5
471 #define TINYFORMAT_PASSARGS_TAIL_6 , v2, v3, v4, v5, v6
472 #define TINYFORMAT_PASSARGS_TAIL_7 , v2, v3, v4, v5, v6, v7
473 #define TINYFORMAT_PASSARGS_TAIL_8 , v2, v3, v4, v5, v6, v7, v8
474 #define TINYFORMAT_PASSARGS_TAIL_9 , v2, v3, v4, v5, v6, v7, v8, v9
475 #define TINYFORMAT_PASSARGS_TAIL_10 , v2, v3, v4, v5, v6, v7, v8, v9, v10
476 #define TINYFORMAT_PASSARGS_TAIL_11 , v2, v3, v4, v5, v6, v7, v8, v9, v10, v11
477 #define TINYFORMAT_PASSARGS_TAIL_12 , v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12
478 #define TINYFORMAT_PASSARGS_TAIL_13 , v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13
479 #define TINYFORMAT_PASSARGS_TAIL_14 , v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14
480 #define TINYFORMAT_PASSARGS_TAIL_15 , v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15
481 #define TINYFORMAT_PASSARGS_TAIL_16 , v2, v3, v4, v5, v6, v7, v8, v9, v10, v11, v12, v13, v14, v15, v16
483 #define TINYFORMAT_FOREACH_ARGNUM(m) \
484 m(1) m(2) m(3) m(4) m(5) m(6) m(7) m(8) m(9) m(10) m(11) m(12) m(13) m(14) m(15) m(16)
485 //[[[end]]]
489 namespace detail {
491 // Type-opaque holder for an argument to format(), with associated actions on
492 // the type held as explicit function pointers. This allows FormatArg's for
493 // each argument to be allocated as a homogenous array inside FormatList
494 // whereas a naive implementation based on inheritance does not.
495 class FormatArg
497 public:
498 FormatArg() {}
500 template<typename T>
501 FormatArg(const T& value)
502 : m_value(static_cast<const void*>(&value)),
503 m_formatImpl(&formatImpl<T>),
504 m_toIntImpl(&toIntImpl<T>)
507 void format(std::ostream& out, const char* fmtBegin,
508 const char* fmtEnd, int ntrunc) const
510 m_formatImpl(out, fmtBegin, fmtEnd, ntrunc, m_value);
513 int toInt() const
515 return m_toIntImpl(m_value);
518 private:
519 template<typename T>
520 TINYFORMAT_HIDDEN static void formatImpl(std::ostream& out, const char* fmtBegin,
521 const char* fmtEnd, int ntrunc, const void* value)
523 formatValue(out, fmtBegin, fmtEnd, ntrunc, *static_cast<const T*>(value));
526 template<typename T>
527 TINYFORMAT_HIDDEN static int toIntImpl(const void* value)
529 return convertToInt<T>::invoke(*static_cast<const T*>(value));
532 const void* m_value;
533 void (*m_formatImpl)(std::ostream& out, const char* fmtBegin,
534 const char* fmtEnd, int ntrunc, const void* value);
535 int (*m_toIntImpl)(const void* value);
539 // Parse and return an integer from the string c, as atoi()
540 // On return, c is set to one past the end of the integer.
541 inline int parseIntAndAdvance(const char*& c)
543 int i = 0;
544 for(;*c >= '0' && *c <= '9'; ++c)
545 i = 10*i + (*c - '0');
546 return i;
549 // Print literal part of format string and return next format spec
550 // position.
552 // Skips over any occurrences of '%%', printing a literal '%' to the
553 // output. The position of the first % character of the next
554 // nontrivial format spec is returned, or the end of string.
555 inline const char* printFormatStringLiteral(std::ostream& out, const char* fmt)
557 const char* c = fmt;
558 for(;; ++c)
560 switch(*c)
562 case '\0':
563 out.write(fmt, c - fmt);
564 return c;
565 case '%':
566 out.write(fmt, c - fmt);
567 if(*(c+1) != '%')
568 return c;
569 // for "%%", tack trailing % onto next literal section.
570 fmt = ++c;
571 break;
572 default:
573 break;
579 // Parse a format string and set the stream state accordingly.
581 // The format mini-language recognized here is meant to be the one from C99,
582 // with the form "%[flags][width][.precision][length]type".
584 // Formatting options which can't be natively represented using the ostream
585 // state are returned in spacePadPositive (for space padded positive numbers)
586 // and ntrunc (for truncating conversions). argIndex is incremented if
587 // necessary to pull out variable width and precision . The function returns a
588 // pointer to the character after the end of the current format spec.
589 inline const char* streamStateFromFormat(std::ostream& out, bool& spacePadPositive,
590 int& ntrunc, const char* fmtStart,
591 const detail::FormatArg* formatters,
592 int& argIndex, int numFormatters)
594 if(*fmtStart != '%')
596 TINYFORMAT_ERROR("tinyformat: Not enough conversion specifiers in format string");
597 return fmtStart;
599 // Reset stream state to defaults.
600 out.width(0);
601 out.precision(6);
602 out.fill(' ');
603 // Reset most flags; ignore irrelevant unitbuf & skipws.
604 out.unsetf(std::ios::adjustfield | std::ios::basefield |
605 std::ios::floatfield | std::ios::showbase | std::ios::boolalpha |
606 std::ios::showpoint | std::ios::showpos | std::ios::uppercase);
607 bool precisionSet = false;
608 bool widthSet = false;
609 int widthExtra = 0;
610 const char* c = fmtStart + 1;
611 // 1) Parse flags
612 for(;; ++c)
614 switch(*c)
616 case '#':
617 out.setf(std::ios::showpoint | std::ios::showbase);
618 continue;
619 case '0':
620 // overridden by left alignment ('-' flag)
621 if(!(out.flags() & std::ios::left))
623 // Use internal padding so that numeric values are
624 // formatted correctly, eg -00010 rather than 000-10
625 out.fill('0');
626 out.setf(std::ios::internal, std::ios::adjustfield);
628 continue;
629 case '-':
630 out.fill(' ');
631 out.setf(std::ios::left, std::ios::adjustfield);
632 continue;
633 case ' ':
634 // overridden by show positive sign, '+' flag.
635 if(!(out.flags() & std::ios::showpos))
636 spacePadPositive = true;
637 continue;
638 case '+':
639 out.setf(std::ios::showpos);
640 spacePadPositive = false;
641 widthExtra = 1;
642 continue;
643 default:
644 break;
646 break;
648 // 2) Parse width
649 if(*c >= '0' && *c <= '9')
651 widthSet = true;
652 out.width(parseIntAndAdvance(c));
654 if(*c == '*')
656 widthSet = true;
657 int width = 0;
658 if(argIndex < numFormatters)
659 width = formatters[argIndex++].toInt();
660 else
661 TINYFORMAT_ERROR("tinyformat: Not enough arguments to read variable width");
662 if(width < 0)
664 // negative widths correspond to '-' flag set
665 out.fill(' ');
666 out.setf(std::ios::left, std::ios::adjustfield);
667 width = -width;
669 out.width(width);
670 ++c;
672 // 3) Parse precision
673 if(*c == '.')
675 ++c;
676 int precision = 0;
677 if(*c == '*')
679 ++c;
680 if(argIndex < numFormatters)
681 precision = formatters[argIndex++].toInt();
682 else
683 TINYFORMAT_ERROR("tinyformat: Not enough arguments to read variable precision");
685 else
687 if(*c >= '0' && *c <= '9')
688 precision = parseIntAndAdvance(c);
689 else if(*c == '-') // negative precisions ignored, treated as zero.
690 parseIntAndAdvance(++c);
692 out.precision(precision);
693 precisionSet = true;
695 // 4) Ignore any C99 length modifier
696 while(*c == 'l' || *c == 'h' || *c == 'L' ||
697 *c == 'j' || *c == 'z' || *c == 't')
698 ++c;
699 // 5) We're up to the conversion specifier character.
700 // Set stream flags based on conversion specifier (thanks to the
701 // boost::format class for forging the way here).
702 bool intConversion = false;
703 switch(*c)
705 case 'u': case 'd': case 'i':
706 out.setf(std::ios::dec, std::ios::basefield);
707 intConversion = true;
708 break;
709 case 'o':
710 out.setf(std::ios::oct, std::ios::basefield);
711 intConversion = true;
712 break;
713 case 'X':
714 out.setf(std::ios::uppercase);
715 case 'x': case 'p':
716 out.setf(std::ios::hex, std::ios::basefield);
717 intConversion = true;
718 break;
719 case 'E':
720 out.setf(std::ios::uppercase);
721 case 'e':
722 out.setf(std::ios::scientific, std::ios::floatfield);
723 out.setf(std::ios::dec, std::ios::basefield);
724 break;
725 case 'F':
726 out.setf(std::ios::uppercase);
727 case 'f':
728 out.setf(std::ios::fixed, std::ios::floatfield);
729 break;
730 case 'G':
731 out.setf(std::ios::uppercase);
732 case 'g':
733 out.setf(std::ios::dec, std::ios::basefield);
734 // As in boost::format, let stream decide float format.
735 out.flags(out.flags() & ~std::ios::floatfield);
736 break;
737 case 'a': case 'A':
738 TINYFORMAT_ERROR("tinyformat: the %a and %A conversion specs "
739 "are not supported");
740 break;
741 case 'c':
742 // Handled as special case inside formatValue()
743 break;
744 case 's':
745 if(precisionSet)
746 ntrunc = static_cast<int>(out.precision());
747 // Make %s print booleans as "true" and "false"
748 out.setf(std::ios::boolalpha);
749 break;
750 case 'n':
751 // Not supported - will cause problems!
752 TINYFORMAT_ERROR("tinyformat: %n conversion spec not supported");
753 break;
754 case '\0':
755 TINYFORMAT_ERROR("tinyformat: Conversion spec incorrectly "
756 "terminated by end of string");
757 return c;
758 default:
759 break;
761 if(intConversion && precisionSet && !widthSet)
763 // "precision" for integers gives the minimum number of digits (to be
764 // padded with zeros on the left). This isn't really supported by the
765 // iostreams, but we can approximately simulate it with the width if
766 // the width isn't otherwise used.
767 out.width(out.precision() + widthExtra);
768 out.setf(std::ios::internal, std::ios::adjustfield);
769 out.fill('0');
771 return c+1;
775 //------------------------------------------------------------------------------
776 inline void formatImpl(std::ostream& out, const char* fmt,
777 const detail::FormatArg* formatters,
778 int numFormatters)
780 // Saved stream state
781 std::streamsize origWidth = out.width();
782 std::streamsize origPrecision = out.precision();
783 std::ios::fmtflags origFlags = out.flags();
784 char origFill = out.fill();
786 for (int argIndex = 0; argIndex < numFormatters; ++argIndex)
788 // Parse the format string
789 fmt = printFormatStringLiteral(out, fmt);
790 bool spacePadPositive = false;
791 int ntrunc = -1;
792 const char* fmtEnd = streamStateFromFormat(out, spacePadPositive, ntrunc, fmt,
793 formatters, argIndex, numFormatters);
794 if (argIndex >= numFormatters)
796 // Check args remain after reading any variable width/precision
797 TINYFORMAT_ERROR("tinyformat: Not enough format arguments");
798 return;
800 const FormatArg& arg = formatters[argIndex];
801 // Format the arg into the stream.
802 if(!spacePadPositive)
803 arg.format(out, fmt, fmtEnd, ntrunc);
804 else
806 // The following is a special case with no direct correspondence
807 // between stream formatting and the printf() behaviour. Simulate
808 // it crudely by formatting into a temporary string stream and
809 // munging the resulting string.
810 std::ostringstream tmpStream;
811 tmpStream.copyfmt(out);
812 tmpStream.setf(std::ios::showpos);
813 arg.format(tmpStream, fmt, fmtEnd, ntrunc);
814 std::string result = tmpStream.str(); // allocates... yuck.
815 for(size_t i = 0, iend = result.size(); i < iend; ++i)
816 if(result[i] == '+') result[i] = ' ';
817 out << result;
819 fmt = fmtEnd;
822 // Print remaining part of format string.
823 fmt = printFormatStringLiteral(out, fmt);
824 if(*fmt != '\0')
825 TINYFORMAT_ERROR("tinyformat: Too many conversion specifiers in format string");
827 // Restore stream state
828 out.width(origWidth);
829 out.precision(origPrecision);
830 out.flags(origFlags);
831 out.fill(origFill);
834 } // namespace detail
837 /// List of template arguments format(), held in a type-opaque way.
839 /// A const reference to FormatList (typedef'd as FormatListRef) may be
840 /// conveniently used to pass arguments to non-template functions: All type
841 /// information has been stripped from the arguments, leaving just enough of a
842 /// common interface to perform formatting as required.
843 class FormatList
845 public:
846 FormatList(detail::FormatArg* formatters, int N)
847 : m_formatters(formatters), m_N(N) { }
849 friend void vformat(std::ostream& out, const char* fmt,
850 const FormatList& list);
852 private:
853 const detail::FormatArg* m_formatters;
854 int m_N;
857 /// Reference to type-opaque format list for passing to vformat()
858 typedef const FormatList& FormatListRef;
861 namespace detail {
863 // Format list subclass with fixed storage to avoid dynamic allocation
864 template<int N>
865 class FormatListN : public FormatList
867 public:
868 #ifdef TINYFORMAT_USE_VARIADIC_TEMPLATES
869 template<typename... Args>
870 FormatListN(const Args&... args)
871 : FormatList(&m_formatterStore[0], N),
872 m_formatterStore { FormatArg(args)... }
873 { static_assert(sizeof...(args) == N, "Number of args must be N"); }
874 #else // C++98 version
875 void init(int) {}
876 # define TINYFORMAT_MAKE_FORMATLIST_CONSTRUCTOR(n) \
878 template<TINYFORMAT_ARGTYPES(n)> \
879 FormatListN(TINYFORMAT_VARARGS(n)) \
880 : FormatList(&m_formatterStore[0], n) \
881 { assert(n == N); init(0, TINYFORMAT_PASSARGS(n)); } \
883 template<TINYFORMAT_ARGTYPES(n)> \
884 void init(int i, TINYFORMAT_VARARGS(n)) \
886 m_formatterStore[i] = FormatArg(v1); \
887 init(i+1 TINYFORMAT_PASSARGS_TAIL(n)); \
890 TINYFORMAT_FOREACH_ARGNUM(TINYFORMAT_MAKE_FORMATLIST_CONSTRUCTOR)
891 # undef TINYFORMAT_MAKE_FORMATLIST_CONSTRUCTOR
892 #endif
894 private:
895 FormatArg m_formatterStore[N];
898 // Special 0-arg version - MSVC says zero-sized C array in struct is nonstandard
899 template<> class FormatListN<0> : public FormatList
901 public: FormatListN() : FormatList(0, 0) {}
904 } // namespace detail
907 //------------------------------------------------------------------------------
908 // Primary API functions
910 #ifdef TINYFORMAT_USE_VARIADIC_TEMPLATES
912 /// Make type-agnostic format list from list of template arguments.
914 /// The exact return type of this function is an implementation detail and
915 /// shouldn't be relied upon. Instead it should be stored as a FormatListRef:
917 /// FormatListRef formatList = makeFormatList( /*...*/ );
918 template<typename... Args>
919 detail::FormatListN<sizeof...(Args)> makeFormatList(const Args&... args)
921 return detail::FormatListN<sizeof...(args)>(args...);
924 #else // C++98 version
926 inline detail::FormatListN<0> makeFormatList()
928 return detail::FormatListN<0>();
930 #define TINYFORMAT_MAKE_MAKEFORMATLIST(n) \
931 template<TINYFORMAT_ARGTYPES(n)> \
932 detail::FormatListN<n> makeFormatList(TINYFORMAT_VARARGS(n)) \
934 return detail::FormatListN<n>(TINYFORMAT_PASSARGS(n)); \
936 TINYFORMAT_FOREACH_ARGNUM(TINYFORMAT_MAKE_MAKEFORMATLIST)
937 #undef TINYFORMAT_MAKE_MAKEFORMATLIST
939 #endif
941 /// Format list of arguments to the stream according to the given format string.
943 /// The name vformat() is chosen for the semantic similarity to vprintf(): the
944 /// list of format arguments is held in a single function argument.
945 inline void vformat(std::ostream& out, const char* fmt, FormatListRef list)
947 detail::formatImpl(out, fmt, list.m_formatters, list.m_N);
951 #ifdef TINYFORMAT_USE_VARIADIC_TEMPLATES
953 /// Format list of arguments to the stream according to given format string.
954 template<typename... Args>
955 void format(std::ostream& out, const char* fmt, const Args&... args)
957 vformat(out, fmt, makeFormatList(args...));
960 /// Format list of arguments according to the given format string and return
961 /// the result as a string.
962 template<typename... Args>
963 std::string format(const char* fmt, const Args&... args)
965 std::ostringstream oss;
966 format(oss, fmt, args...);
967 return oss.str();
970 /// Format list of arguments to std::cout, according to the given format string
971 template<typename... Args>
972 void printf(const char* fmt, const Args&... args)
974 format(std::cout, fmt, args...);
977 template<typename... Args>
978 void printfln(const char* fmt, const Args&... args)
980 format(std::cout, fmt, args...);
981 std::cout << '\n';
984 #else // C++98 version
986 inline void format(std::ostream& out, const char* fmt)
988 vformat(out, fmt, makeFormatList());
991 inline std::string format(const char* fmt)
993 std::ostringstream oss;
994 format(oss, fmt);
995 return oss.str();
998 inline void printf(const char* fmt)
1000 format(std::cout, fmt);
1003 inline void printfln(const char* fmt)
1005 format(std::cout, fmt);
1006 std::cout << '\n';
1009 #define TINYFORMAT_MAKE_FORMAT_FUNCS(n) \
1011 template<TINYFORMAT_ARGTYPES(n)> \
1012 void format(std::ostream& out, const char* fmt, TINYFORMAT_VARARGS(n)) \
1014 vformat(out, fmt, makeFormatList(TINYFORMAT_PASSARGS(n))); \
1017 template<TINYFORMAT_ARGTYPES(n)> \
1018 std::string format(const char* fmt, TINYFORMAT_VARARGS(n)) \
1020 std::ostringstream oss; \
1021 format(oss, fmt, TINYFORMAT_PASSARGS(n)); \
1022 return oss.str(); \
1025 template<TINYFORMAT_ARGTYPES(n)> \
1026 void printf(const char* fmt, TINYFORMAT_VARARGS(n)) \
1028 format(std::cout, fmt, TINYFORMAT_PASSARGS(n)); \
1031 template<TINYFORMAT_ARGTYPES(n)> \
1032 void printfln(const char* fmt, TINYFORMAT_VARARGS(n)) \
1034 format(std::cout, fmt, TINYFORMAT_PASSARGS(n)); \
1035 std::cout << '\n'; \
1038 TINYFORMAT_FOREACH_ARGNUM(TINYFORMAT_MAKE_FORMAT_FUNCS)
1039 #undef TINYFORMAT_MAKE_FORMAT_FUNCS
1041 #endif
1043 // Added for Bitcoin Core
1044 template<typename... Args>
1045 std::string format(const std::string &fmt, const Args&... args)
1047 std::ostringstream oss;
1048 format(oss, fmt.c_str(), args...);
1049 return oss.str();
1052 } // namespace tinyformat
1054 #define strprintf tfm::format
1056 #endif // TINYFORMAT_H_INCLUDED