xtd::collections::generic::helpers::lesser< type_t > Struct Template Reference

Definition

template<class type_t = void>
struct xtd::collections::generic::helpers::lesser< type_t >

Implements a function object for compare data.

struct lesser;

Header

#include <xtd/collections/generic/helpers/lesser>

Namespace

xtd::collections::generic::helpers

Library

xtd.core

Remarks

The associative containers xtd::collections::generic::sorted_set, xtd::collections::generic::sorted_multi_set, xtd::collections::generic::sorted_dictionary, xtd::collections::generic::sorted_multi_dictionary use specializations of the template xtd::collections::generic::helpers::lesser as the defaultcompare function.

Examples

The following example show how to use xtd::collections::generic::helpers::lesser with std::unordered_map.

auto key_values = std::map<xtd::date_time, xtd::string, xtd::collections::generic::helpers::lesser<xtd::date_time>, xtd::collections::generic::helpers::allocator<xtd::collections::generic::key_value_pair<const xtd::date_time, xtd::string>>> {};
key_values.insert({{1971, 1, 5}, "Birth date"});

Public Aliases
using	first_argument_type
	Represents the first argument type.
using	second_argument_type
	Represents the second argument type.
using	result_type
	Represents the result type.

Public Constructors
	lesser ()=default
	Initializes a new instance of the comparer.
	lesser (const xtd::collections::generic::icomparer< type_t > &comparer)
	Initializes a new instance of the comparer with specified comparer.

Public Operators
constexpr auto	operator() (const first_argument_type &lhs, const second_argument_type &rhs) const -> result_type
	Serves as a hash function for a specified key with a particular type (type_t).

Member Typedef Documentation

first_argument_type

template<class type_t = void>

using xtd::collections::generic::helpers::lesser< type_t >::first_argument_type

Represents the first argument type.

second_argument_type

template<class type_t = void>

using xtd::collections::generic::helpers::lesser< type_t >::second_argument_type

Represents the second argument type.

result_type

template<class type_t = void>

using xtd::collections::generic::helpers::lesser< type_t >::result_type

Represents the result type.

Constructor & Destructor Documentation

lesser() [1/2]

template<class type_t = void>

xtd::collections::generic::helpers::lesser< type_t >::lesser ( )

default

Initializes a new instance of the comparer.

lesser() [2/2]

template<class type_t = void>

xtd::collections::generic::helpers::lesser< type_t >::lesser ( const xtd::collections::generic::icomparer< type_t > & comparer )

inlineexplicit

Initializes a new instance of the comparer with specified comparer.

Parameters

comparer

A comparer used to hash the key.

Member Function Documentation

operator()()

template<class type_t = void>

auto xtd::collections::generic::helpers::lesser< type_t >::operator() ( const first_argument_type & lhs, const second_argument_type & rhs ) const -> result_type

inlineconstexpr

Serves as a hash function for a specified key with a particular type (type_t).

Parameters

key	The key to hash.

Returns

A hash code for the spesified key.

Remarks

If key_t inherits from xtd::object, the xtd::object::get_hash_code method will be used; otherwise, the std::hash object function will be used.

---

The documentation for this struct was generated from the following file:

• xtd.core/include/xtd/collections/generic/helpers/lesser.hpp