hash_map::lower_bound (STL/CLR)

Article
06/05/2017

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The latest version of this topic can be found at hash_map::lower_bound (STL/CLR).

Finds beginning of range that matches a specified key.

Syntax

iterator lower_bound(key_type key);

Parameters

key
Key value to search for.

Remarks

The member function determines the first element X in the controlled sequence that hashes to the same bucket as key and has equivalent ordering to key. If no such element exists, it returns hash_map::end (STL/CLR)(); otherwise it returns an iterator that designates X. You use it to locate the beginning of a sequence of elements currently in the controlled sequence that match a specified key.

Example

// cliext_hash_map_lower_bound.cpp   
// compile with: /clr   
#include <cliext/hash_map>   
  
typedef cliext::hash_map<wchar_t, int> Myhash_map;   
int main()   
    {   
    Myhash_map c1;   
    c1.insert(Myhash_map::make_value(L'a', 1));   
    c1.insert(Myhash_map::make_value(L'b', 2));   
    c1.insert(Myhash_map::make_value(L'c', 3));   
  
// display contents " [a 1] [b 2] [c 3]"   
    for each (Myhash_map::value_type elem in c1)   
        System::Console::Write(" [{0} {1}]", elem->first, elem->second);   
    System::Console::WriteLine();   
  
    System::Console::WriteLine("lower_bound(L'x')==end() = {0}",   
        c1.lower_bound(L'x') == c1.end());   
  
    Myhash_map::iterator it = c1.lower_bound(L'a');   
    System::Console::WriteLine("*lower_bound(L'a') = [{0} {1}]",   
        it->first, it->second);   
    it = c1.lower_bound(L'b');   
    System::Console::WriteLine("*lower_bound(L'b') = [{0} {1}]",   
        it->first, it->second);   
    return (0);   
    }

 [a 1] [b 2] [c 3]  
lower_bound
(L'x')==end
() = True  
*lower_bound
(L'a') = [a 1]  
*lower_bound
(L'b') = [b 2]

Requirements

Header: <cliext/hash_map>

Namespace: cliext

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