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std::flat_m...:value_comp(3) C++ Standard Libary std::flat_m...:value_comp(3) NAME std::flat_multimap::value_comp - std::flat_multimap::value_comp Synopsis std::flat_multimap::value_compare value_comp() const; (since C++23) Returns a function object that compares objects of type std::flat_multimap::value_type (key-value pairs) by using key_comp to compare the first components of the pairs. Parameters (none) Return value The value comparison function object. Complexity Constant. Example // Run this code #include <iostream> #include <flat_map> #include <utility> // Example module 97 key compare function struct ModCmp { bool operator()(int lhs, int rhs) const { return (lhs % 97) < (rhs % 97); } }; int main() { std::flat_multimap<int, char, ModCmp> cont; cont = {{1, 'a'}, {2, 'b'}, {3, 'c'}, {4, 'd'}, {5, 'e'}}; auto comp_func = cont.value_comp(); for (const std::pair<int, char> val = {100, 'a'}; auto it : cont) { const bool before = comp_func(it, val); const bool after = comp_func(val, it); std::cout << '(' << it.first << ',' << it.second << ") "; if (!before && !after) std::cout << "equivalent to key (" << val.first << ")\n"; else if (before) std::cout << "goes before key (" << val.first << ")\n"; else if (after) std::cout << "goes after key (" << val.first << ")\n"; else std::unreachable(); } } Output: (1,a) goes before key (100) (2,b) goes before key (100) (3,c) equivalent to key (100) (4,d) goes after key (100) (5,e) goes after key (100) See also key_comp returns the function that compares keys (public member function) http://cppreference.com 2024.06.10 std::flat_m...:value_comp(3)
NAME | Synopsis | Parameters | Return value | Complexity | Example | Output: | See also
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