std::set::lower_bound
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|   iterator lower_bound( const Key& key ); 
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|   const_iterator lower_bound( const Key& key ) const; 
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Returns an iterator pointing to the first element that is not less than key.
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[edit] Parameters
| key | - | key value to compare the elements to | 
[edit] 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.
[edit] Complexity
Logarithmic in the size of the container.
[edit] See also
|    returns range of elements matching a specific key  (public member function)  | 
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|    returns an iterator to the first element greater than a certain value  (public member function)  | 
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