std::multimap<Key,T,Compare,Allocator>::merge

Since C++17

Attempts to extract (“splice”) each element in source and insert it into *this using the comparison object of *this.

# Declarations

template< class C2 >
void merge( std::map<Key, T, C2, Allocator>& source );

(since C++17)

template< class C2 >
void merge( std::map<Key, T, C2, Allocator>&& source );

(since C++17)

template< class C2 >
void merge( std::multimap<Key, T, C2, Allocator>& source );

(since C++17)

template< class C2 >
void merge( std::multimap<Key, T, C2, Allocator>&& source );

(since C++17)

# Parameters

# Return value

(none)

# Example

#include <iostream>
#include <map>
#include <string>
 
int main()
{
    std::multimap<int, std::string> ma{{1, "apple"}, {5, "pear"}, {10, "banana"}};
    std::multimap<int, std::string> mb{{2, "zorro"}, {4, "batman"}, {5, "X"}, {8, "alpaca"}};
    std::multimap<int, std::string> u;
    u.merge(ma);
    std::cout << "ma.size(): " << ma.size() << '\n';
    u.merge(mb);
    std::cout << "mb.size(): " << mb.size() << '\n';
 
    for (auto const& kv : u)
        std::cout << kv.first << ", " << kv.second << '\n';
}

# See also