initializer_list.h

//   Copyright 2016-2023 Jean-Francois Poilpret
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.
 
#ifndef INITIALIZER_LIST_HH
#define INITIALIZER_LIST_HH
 
#include <stddef.h>
 
namespace std
{
    template<class T> class initializer_list
    {
    private:
        const T* array_ = nullptr;
        size_t len_ = 0;
 
        // The compiler can (and will) call a private constructor.
        // This constructor will get called when the compiler encounters a braced
        // list expression with elements of type T, like in f({t1, t2, t3}) and
        // an initializer_list<T> is expected by f function.
        constexpr initializer_list(const T* array, size_t len) : array_{array}, len_{len} {}
 
    public:
        constexpr initializer_list() = default;
 
        constexpr size_t size() const
        {
            return len_;
        }
 
        constexpr const T* begin() const
        {
            return array_;
        }
 
        constexpr const T* end() const
        {
            return begin() + size();
        }
    };
}
 
#endif /* INITIALIZER_LIST_HH */