std::map lower_bound() method

since C++14

// (1) Non const version
iterator lower_bound( const Key& key );

// (2) Const version
const_iterator lower_bound( const Key& key ) const;

// (3) Non const version
template< class K >
iterator lower_bound( const K& x );

// (4) Const version
template< class K >
const_iterator lower_bound( const K& x ) const;

since C++98

// (1) Non const version
iterator lower_bound( const Key& key );

// (2) Const version
const_iterator lower_bound( const Key& key ) const;

• (1-2) Returns an iterator pointing to the first element that is not less than (i.e. greater or equal to) key.
• (3,4) Returns an iterator pointing to the first element that compares not less (i.e. greater or equal) to the value x. This overload participates in overload resolution only if the qualified-id Compare::is_transparent is valid and denotes a type. It allows calling this function without constructing an instance of Key.

Parameters

• key - key value of the elements to count
• x - a value of any type that can be transparently compared with a key

Return value

Iterator pointing to the first element that is not less than key. If no such element is found, a past-the-end iterator (see end()) is returned.

Complexity

Logarithmic in the size of the container - O(log size()).

Exceptions

(none)

Notes

Feature testing macro: __cpp_lib_generic_associative_lookup (for overloads (3) and (4)).