Defined in header <fkYAML/node.hpp>
fkyaml::basic_node::contains¶
template <
typename KeyType, detail::enable_if_t<
detail::conjunction<
detail::negation<detail::is_basic_node<detail::remove_cvref_t<KeyType>>>,
detail::is_node_compatible_type<basic_node, detail::remove_cvref_t<KeyType>>>::value,
int> = 0>
bool contains(KeyType&& key) const; // (1) A compatible key object with basic_node type
template <
typename KeyType, detail::enable_if_t<detail::is_basic_node<detail::remove_cvref_t<KeyType>>::value, int> = 0>
bool contains(KeyType&& key) const; // (2) A basic_node object
Checks if the YAML node has the given key.
If the node value is not a mapping, this API will throw an fkyaml::type_error.
The KeyType can be a compatible type with fkyaml::basic_node or a kind of fkyaml::basic_node template class.
Template Parameters¶
- KeyType
- A type which is compatible with or a kind of
fkyaml::basic_node.
Parameters¶
key[in]- A key to the target value in the YAML mapping node value.
Return Value¶
true if the YAML node is a mapping and has the given key, false otherwise.
Example
#include <iomanip>
#include <iostream>
#include <fkYAML/node.hpp>
int main() {
// create a YAML mapping node.
fkyaml::node n = {{"foo", true}, {"bar", 123}};
// check if the node has the following keys.
std::cout << std::boolalpha;
std::cout << n.contains("foo") << std::endl;
std::cout << n.contains(fkyaml::node("baz")) << std::endl;
// create a YAML node. (not mapping)
fkyaml::node n2 = "qux";
// check if the node has the following key.
std::cout << std::boolalpha << n2.contains("qux") << std::endl;
return 0;
}
output: