libcxx/test/std/containers/container.adaptors/flat.multimap/flat.multimap.cons/deduct.verify.cpp

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20

// <flat_map>

// Test CTAD on cases where deduction should fail.

#include <flat_map>
#include <functional>
#include <utility>

struct NotAnAllocator {
  friend bool operator<(NotAnAllocator, NotAnAllocator) { return false; }
};

using P  = std::pair<int, long>;
using PC = std::pair<const int, long>;

void test() {
  {
    // cannot deduce that the inner braced things should be std::pair and not something else
    std::flat_multimap m{{1, 1L}, {2, 2L}, {3, 3L}};
    // expected-error-re@-1{{{{no viable constructor or deduction guide for deduction of template arguments of '.*flat_multimap'}}}}
  }
  {
    // cannot deduce that the inner braced things should be std::pair and not something else
    std::flat_multimap m({{1, 1L}, {2, 2L}, {3, 3L}}, std::less<int>());
    // expected-error-re@-1{{{{no viable constructor or deduction guide for deduction of template arguments of '.*flat_multimap'}}}}
  }
  {
    // cannot deduce that the inner braced things should be std::pair and not something else
    std::flat_multimap m({{1, 1L}, {2, 2L}, {3, 3L}}, std::less<int>(), std::allocator<PC>());
    // expected-error-re@-1{{{{no viable constructor or deduction guide for deduction of template arguments of '.*flat_multimap'}}}}
  }
  {
    // cannot deduce that the inner braced things should be std::pair and not something else
    std::flat_multimap m({{1, 1L}, {2, 2L}, {3, 3L}}, std::allocator<PC>());
    // expected-error-re@-1{{{{no viable constructor or deduction guide for deduction of template arguments of '.*flat_multimap'}}}}
  }
  {
    // since we have parens, not braces, this deliberately does not find the initializer_list constructor
    std::flat_multimap m(P{1, 1L});
    // expected-error-re@-1{{{{no viable constructor or deduction guide for deduction of template arguments of '.*flat_multimap'}}}}
  }
  {
    // since we have parens, not braces, this deliberately does not find the initializer_list constructor
    std::flat_multimap m(PC{1, 1L});
    // expected-error-re@-1{{{{no viable constructor or deduction guide for deduction of template arguments of '.*flat_multimap'}}}}
  }
}