libcxx/test/std/utilities/format/format.functions/format.verify.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // UNSUPPORTED: c++03, c++11, c++14, c++17
  10
  11 // TODO FMT This test should not require std::to_chars(floating-point)
  12 // XFAIL: availability-fp_to_chars-missing
  13
  14 // Basic test to validate ill-formed code is properly detected.
  15
  16 // <format>
  17
  18 // template<class... Args>
  19 //   string format(format-string<Args...> fmt, const Args&... args);
  20 // template<class... Args>
  21 //   wstring format(wformat-string<Args...> fmt, const Args&... args);
  22
  23 #include <format>
  24
  25 #include "test_macros.h"
  26
  27 // clang-format off
  28
  29 void f() {
  30   TEST_IGNORE_NODISCARD std::format("{"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  31   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  32
  33   TEST_IGNORE_NODISCARD std::format("}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  34   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  35
  36   TEST_IGNORE_NODISCARD std::format("{}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  37   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  38
  39   TEST_IGNORE_NODISCARD std::format("{0}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  40   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  41
  42   TEST_IGNORE_NODISCARD std::format("{:-}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  43   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  44
  45   TEST_IGNORE_NODISCARD std::format("{:#}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  46   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  47
  48   TEST_IGNORE_NODISCARD std::format("{:L}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  49   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  50
  51   TEST_IGNORE_NODISCARD std::format("{0:{0}}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  52   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  53
  54   TEST_IGNORE_NODISCARD std::format("{:.42d}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  55   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  56
  57   TEST_IGNORE_NODISCARD std::format("{:d}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  58   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  59
  60 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
  61   TEST_IGNORE_NODISCARD std::format(L"{"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  62   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  63
  64   TEST_IGNORE_NODISCARD std::format(L"}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  65   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  66
  67   TEST_IGNORE_NODISCARD std::format(L"{}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  68   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  69
  70   TEST_IGNORE_NODISCARD std::format(L"{0}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  71   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  72
  73   TEST_IGNORE_NODISCARD std::format(L"{:-}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  74   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  75
  76   TEST_IGNORE_NODISCARD std::format(L"{:#}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  77   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  78
  79   TEST_IGNORE_NODISCARD std::format(L"{:L}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  80   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  81
  82   TEST_IGNORE_NODISCARD std::format(L"{0:{0}}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  83   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  84
  85   TEST_IGNORE_NODISCARD std::format(L"{:.42d}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  86   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  87
  88   TEST_IGNORE_NODISCARD std::format(L"{:d}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
  89   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
  90 #endif
  91 }
  92
  93 struct tiny {
  94   int bit : 1;
  95 };
  96
  97 void P2418()
  98 {
  99   auto t = tiny{};
 100   TEST_IGNORE_NODISCARD std::format("{}", t.bit); // expected-error{{non-const reference cannot bind to bit-field 'bit'}}
 101
 102 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 103   TEST_IGNORE_NODISCARD std::format(L"{}", t.bit); // expected-error{{non-const reference cannot bind to bit-field 'bit'}}
 104 #endif
 105 }