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std::map<Key,T,Compare,Allocator>:: lower_bound

From cppreference.net

iterator lower_bound ( const Key & key ) ;
(1) (constexpr since C++26)
const_iterator lower_bound ( const Key & key ) const ;
(2) (constexpr since C++26)
template < class K >
iterator lower_bound ( const K & x ) ;
(3) (since C++14)
(constexpr since C++26)
template < class K >
const_iterator lower_bound ( const K & x ) const ;
(4) (since C++14)
(constexpr since C++26)
1,2) Returns an iterator pointing to the first element that is not less than key .
3,4) Returns an iterator pointing to the first element that compares not less than x .
This overload participates in overload resolution only if Compare is transparent . It allows calling this function without constructing an instance of Key .

Contents

Parameters

key - key value to compare the elements to
x - alternative value that can be compared to Key

Return value

An iterator pointing to the first element that is not less than the given key, or end ( ) is no such element exists.

Complexity

Logarithmic in the size of the container.

Notes

Feature-test macro Value Std Feature
__cpp_lib_generic_associative_lookup 201304L (C++14) Heterogeneous comparison lookup in associative containers ; overloads ( 3,4 )

Example

See also

returns range of elements matching a specific key
(public member function)
returns an iterator to the first element greater than the given key
(public member function)