Emplace a value for movable key at hint if missing.
Declared in <bslstl_unorderedmap.h>
template<class... Args>
iterator
try_emplace(
const_iterator hint,
BloombergLP::bslmf::MovableRef<KEY> key,
Args&&... args);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.
iterator to the existing or newly inserted element
| Name | Description |
|---|---|
| hint | iterator hint for insertion |
| key | key to look up |
| args | constructor arguments for the new element |