exchange.hpp File Reference

#include "forward.hpp"
#include "move.hpp"

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Functions
template<typename T , typename U = T>
constexpr T	bsl::exchange (T &obj, U &&new_value) noexcept(false)
	Replaces the value of obj with new_value and returns the old value of obj. More...

Detailed Description

Copyright

Copyright (C) 2020 Assured Information Security, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Function Documentation

exchange()

template<typename T , typename U = T>

constexpr T bsl::exchange ( T &  obj, U &&  new_value  )

noexcept

Replaces the value of obj with new_value and returns the old value of obj.

#include <bsl/exchange.hpp>
#include <bsl/debug.hpp>

namespace bsl
{
    inline void
    example_exchange_overview() noexcept
    {
        bsl::int32 const val1{23};
        bsl::int32 const val2{42};

        bsl::int32 var1{val1};
        bsl::int32 var2{val2};
        var2 = bsl::exchange(var1, var2);

        if (val2 == var1) {
            bsl::print() << "success\n";
        }

        if (val1 == var2) {
            bsl::print() << "success\n";
        }
    }
}

Template Parameters

T	the type that defines the obj being exchanged
U	the type that defines the new value for obj

Parameters

obj	the object whose value will be set to new_value
new_value	the new value to set the obj to

Returns

returns the old value of obj prior to the exchange

Exceptions

throws

if obj's move constructor or obj's copy/move assignment throws