std::experimental::optional::emplace

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

Experimental libraries

Experimental standard libraries

optional (library fundamentals TS)

any (library fundamentals TS)

basic_string_view (library fundamentals TS)

Polymorphic allocator library (library fundamentals TS)

Filesystem library (filesystem TS)

 

std::experimental::optional

Member functions

optional::optional

optional::~optional

optional::operator=

Observers

optional::operator->optional::operator*

optional::operator bool

optional::value

optional::value_or

Modifiers

optional::emplace

optional::swap

Non-member functions

operator==operator<

make_optional

swap

Helper classes

hash

 

template< class... Args > void emplace( Args&&... args );		(library fundamentals TS)
template< class U, class... Args > void emplace( std::initializer_list<U> ilist, Args&&... args );		(library fundamentals TS)

Constructs the contained value in-place. If *this is in engaged state before the call, the contained value is destroyed by calling its destructor.

1) Initializes the contained value by calling its constructor with args... as parameters.

2) Initializes the contained value by calling its constructor with ilist and args... as parameters.

Parameters

args...	-	the arguments to pass to the constructor
ilist	-	the initializer list to pass to the constructor
Type requirements
- T must be constructible from Args...
- T must be constructible from std::initializer_list and Args...

Return value

(none)

Exceptions

Any exception thrown by the selected constructor of T. If an exception is thrown, *this is in disengaged state after the call.

See also

operator=

assigns contents (public member function)