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Defined in header <fkYAML/node.hpp>

fkyaml::ordered_map::operator[]

template <
    typename KeyType,
    detail::enable_if_t<detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value, int> = 0>
mapped_type& operator[](KeyType&& key) noexcept;

Accesses an element with the given key.

Tip

This API behaves like the std::map class does.
In other words, it does not check the existence of the given key, and could return a default value if the key does not exist.
To avoid such a behavior, you can use at() function which throws a fkyaml::exception if the given key does not match any keys in the ordered_map object.

Template Parameters

KeyType
A type compatible with the key type.

Parameters

key [in]
A key to the target value.

Return Value

Reference to a mapped_type object associated with the given key.
Possibly a default value of the mapped_type if the ordered_map does not contain the given key.

Example 
#include <iostream>
#include <fkYAML/node.hpp>
#include <fkYAML/ordered_map.hpp>

int main() {
    fkyaml::ordered_map<std::string, fkyaml::node> om = {{"foo", 123}, {"bar", "baz"}};

    std::cout << om["foo"] << std::endl;
    std::cout << om["bar"] << std::endl;

    // accesses with a unknown key will create a new key-value pair with the default value.
    std::cout << om["qux"] << std::endl;

    return 0;
}

output: 

123
baz
null

See Also