Skip to content

Defined in header <fkYAML/node.hpp>

fkyaml::basic_node::operator<

bool operator<(const basic_node& rhs) const noexcept;

Check if this object is less than rhs according to the following rules:

  • If the values are of the same node_type type, their stored values are compared according to their respective operator<.
  • Two basic_node objects are always equal if both of them are of the node_type::NULL_OBJECT type.
  • If the values are of different node_type types, the stored values are ignored and the order of the types are considered. The order of the types is as followed (top < bottom):
    • node_type::SEQUENCE
    • node_type::MAPPING
    • node_type::NULL_OBJECT
    • node_type::BOOLEAN
    • node_type::INTEGER
    • node_type::FLOAT
    • node_type::STRING
  • If the values are of the node_type::BOOLEAN type, a value whose stored value is false is less than a value whose stored value is true.

Parameters

rhs [in]
A basic_node object to compared with.

Return Value

true if this is less than rhs, false otherwise.

Examples

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

int main() {
    // create YAML nodes.
    fkyaml::node seq_1 = {1, 2, 3};
    fkyaml::node seq_2 = {1, 2, 4};
    fkyaml::node map_1 = {{"foo", true}, {"bar", 123}};
    fkyaml::node map_2 = {{"bar", 123}, {"foo", true}};
    fkyaml::node null_1 = nullptr;
    fkyaml::node null_2 = nullptr;
    fkyaml::node bool_1 = false;
    fkyaml::node bool_2 = true;
    fkyaml::node integer_1 = 321;
    fkyaml::node integer_2 = 123;
    fkyaml::node float_1 = 1.23;
    fkyaml::node float_2 = 3.14;
    fkyaml::node string_1 = "foo";
    fkyaml::node string_2 = "bar";

    // the same type
    std::cout << std::boolalpha;
    std::cout << (seq_1 < seq_2) << std::endl;
    std::cout << (map_1 < map_2) << std::endl;
    std::cout << (null_1 < null_2) << std::endl;
    std::cout << (bool_1 < bool_2) << std::endl;
    std::cout << (integer_1 < integer_2) << std::endl;
    std::cout << (float_1 < float_2) << std::endl;
    std::cout << (string_1 < string_2) << std::endl;

    // different types
    std::cout << (bool_1 < string_1) << std::endl;
    std::cout << (float_2 < seq_2) << std::endl;

    return 0;
}

output: 

true
false
false
true
false
true
false
true
false

See Also