Emplace a value for movable key at hint if missing.

Synopsis

Declared in <bslstl_unorderedmap.h>

template<class... Args>
iterator
try_emplace(
    const_iterator hint,
    BloombergLP::bslmf::MovableRef<KEY> key,
    Args&&... args);

Description

Emplace a value for key if no equivalent key already exists.

If a key equivalent to the specified key already exists in this unordered_map, return an iterator referring to the existing item. Otherwise, insert into this map a newly‐created value_type object, constructed from std::forward<KEY>(key) and the specified args, and return an iterator referring to the newly‐created entry. Use the specified hint as a starting point for checking to see if the key already in the unordered_map. This method requires that the (template parameter) types KEY and VALUE are emplace‐constructible from key and args respectively. For C++03, VALUE must also be copy‐constructible.

Return Value

iterator to the existing or newly inserted element

Parameters

Name

Description

hint

iterator hint for insertion

key

key to look up

args

constructor arguments for the new element

Created with MrDocs