libcxx/test/std/containers/container.adaptors/flat.map/flat.map.erasure/erase_if.pass.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, c++20
  10
  11 // <flat_map>
  12
  13 // template<class Key, class T, class Compare, class KeyContainer, class MappedContainer, class Predicate>
  14 //   typename flat_map<Key, T, Compare, KeyContainer, MappedContainer>::size_type
  15 //   erase_if(flat_map<Key, T, Compare, KeyContainer, MappedContainer>& c, Predicate pred);
  16
  17 #include <deque>
  18 #include <flat_map>
  19 #include <functional>
  20 #include <initializer_list>
  21 #include <vector>
  22
  23 #include "test_macros.h"
  24 #include "test_allocator.h"
  25 #include "min_allocator.h"
  26
  27 // Verify that `flat_map` (like `map`) does NOT support std::erase.
  28 //
  29 template <class S>
  30 concept HasStdErase = requires(S& s, typename S::value_type x) { std::erase(s, x); };
  31 static_assert(HasStdErase<std::vector<int>>);
  32 static_assert(!HasStdErase<std::flat_map<int, int>>);
  33
  34 template <class M>
  35 M make(std::initializer_list<int> vals) {
  36   M ret;
  37   for (int v : vals)
  38     ret[static_cast<typename M::key_type>(v)] = static_cast<typename M::mapped_type>(v + 10);
  39   return ret;
  40 }
  41
  42 template <class M, class Pred>
  43 void test0(
  44     std::initializer_list<int> vals, Pred p, std::initializer_list<int> expected, std::size_t expected_erased_count) {
  45   M s = make<M>(vals);
  46   ASSERT_SAME_TYPE(typename M::size_type, decltype(std::erase_if(s, p)));
  47   assert(expected_erased_count == std::erase_if(s, p));
  48   assert(s == make<M>(expected));
  49 }
  50
  51 template <class S>
  52 void test() {
  53   // Test all the plausible signatures for this predicate.
  54   auto is1   = [](typename S::const_reference v) { return v.first == 1; };
  55   auto is2   = [](typename S::value_type v) { return v.first == 2; };
  56   auto is3   = [](const typename S::value_type& v) { return v.first == 3; };
  57   auto is4   = [](auto v) { return v.first == 4; };
  58   auto True  = [](const auto&) { return true; };
  59   auto False = [](auto&&) { return false; };
  60
  61   test0<S>({}, is1, {}, 0);
  62
  63   test0<S>({1}, is1, {}, 1);
  64   test0<S>({1}, is2, {1}, 0);
  65
  66   test0<S>({1, 2}, is1, {2}, 1);
  67   test0<S>({1, 2}, is2, {1}, 1);
  68   test0<S>({1, 2}, is3, {1, 2}, 0);
  69
  70   test0<S>({1, 2, 3}, is1, {2, 3}, 1);
  71   test0<S>({1, 2, 3}, is2, {1, 3}, 1);
  72   test0<S>({1, 2, 3}, is3, {1, 2}, 1);
  73   test0<S>({1, 2, 3}, is4, {1, 2, 3}, 0);
  74
  75   test0<S>({1, 2, 3}, True, {}, 3);
  76   test0<S>({1, 2, 3}, False, {1, 2, 3}, 0);
  77 }
  78
  79 int main(int, char**) {
  80   test<std::flat_map<int, char>>();
  81   test<std::flat_map<int,
  82                      char,
  83                      std::less<int>,
  84                      std::vector<int, min_allocator<int>>,
  85                      std::vector<char, min_allocator<char>>>>();
  86   test<std::flat_map<int, char, std::greater<int>, std::vector<int, test_allocator<int>>>>();
  87   test<std::flat_map<int, char, std::less<int>, std::deque<int, min_allocator<int>>>>();
  88   test<std::flat_map<int, char, std::greater<int>, std::deque<int, test_allocator<int>>>>();
  89   test<std::flat_map<long, int>>();
  90   test<std::flat_map<double, int>>();
  91
  92   return 0;
  93 }