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std::experimental::ranges::exchange

From cppreference.com
< cpp‎ | experimental‎ | ranges
 
 
Technical specifications
Filesystem library (filesystem TS)
Library fundamentals (library fundamentals TS)
Library fundamentals 2 (library fundamentals 2 TS)
Extensions for parallelism (parallelism TS)
Extensions for parallelism 2 (parallelism TS v2)
Extensions for concurrency (concurrency TS)
Concepts (concepts TS)
Ranges (ranges TS)
Mathematical special functions (special functions TR)
 
 
General utilities library
Utility components
exchange
Function objects
Metaprogramming and type traits
Tagged pairs and tuples
                                        
                                        
                                        
                                        
 
template< MoveConstructible T, class U = T >

    requires Assignable<T&, U>

constexpr T exchange(T& obj, U&& new_val) noexcept(/* see below */);
(ranges TS)

Replaces the value of obj with new_value and returns the old value of obj, as if by

T old_value = std::move(obj);
obj = std::forward<U>(new_value);
return old_value;

Contents

[edit] Parameters

obj - object whose value to replace
new_value - the value to assign to obj

[edit] Return value

The old value of obj

[edit] Exceptions

noexcept specification:  
noexcept(std::is_nothrow_move_constructible<T>::value &&
         std::is_nothrow_assignable<T&, U>::value)

[edit] Example

[edit] See also

(C++14)
replaces the argument with a new value and returns its previous value
(function template) [edit]