xtd::icomparable< type_t > Class Template Reference

Inheritance diagram for xtd::icomparable< type_t >:

Definition

template<typename type_t>
class xtd::icomparable< type_t >

Defines a generalized comparison method that a value type or class implements to create a type-specific comparison method.

Namespace

xtd

Library

xtd.core

Examples

The following example shows how to use xtd::icomparable interface.

#include <xtd/console>
#include <xtd/icomparable>
 
using namespace xtd;
 
class foo : public icomparable<foo> {
public:
  explicit foo(int value) : value_ {value} {}
 
  int compare_to(const foo& value) const noexcept override {
    if (value_ < value.value_) return -1;
    if (value_ > value.value_) return 1;
    return 0;
  }
  
private:
  int value_ = 0;
};
 
auto main() -> int {
  console::write_line("foo {{42}}.compare_to(foo {{42}}) = {}", foo {42}.compare_to(foo {42}));
  console::write_line("foo {{42}}.compare_to(foo {{41}}) = {}", foo {42}.compare_to(foo {41}));
  console::write_line("foo {{42}}.compare_to(foo {{43}}) = {}", foo {42}.compare_to(foo {43}));
  console::write_line();
 
  console::write_line("foo {{42}} <=> foo {{42}} = {}", foo {42} <=> foo {42});
  console::write_line("foo {{42}} <=> foo {{41}} = {}", foo {42} <=> foo {41});
  console::write_line("foo {{42}} <=> foo {{43}} = {}", foo {42} <=> foo {43});
  console::write_line();
  
  console::write_line("foo {{42}} <= foo {{42}} = {}", foo {42} <= foo {42});
  console::write_line("foo {{42}} <= foo {{41}} = {}", foo {42} <= foo {41});
  console::write_line("foo {{42}} <= foo {{43}} = {}", foo {42} <= foo {43});
  console::write_line();
 
  console::write_line("foo {{42}} < foo {{42}} = {}", foo {42} < foo {42});
  console::write_line("foo {{42}} < foo {{41}} = {}", foo {42} < foo {41});
  console::write_line("foo {{42}} < foo {{43}} = {}", foo {42} < foo {43});
  console::write_line();
 
  console::write_line("foo {{42}} >= foo {{42}} = {}", foo {42} >= foo {42});
  console::write_line("foo {{42}} >= foo {{41}} = {}", foo {42} >= foo {41});
  console::write_line("foo {{42}} >= foo {{43}} = {}", foo {42} >= foo {43});
  console::write_line();
 
  console::write_line("foo {{42}} > foo {{42}} = {}", foo {42} > foo {42});
  console::write_line("foo {{42}} > foo {{41}} = {}", foo {42} > foo {41});
  console::write_line("foo {{42}} > foo {{43}} = {}", foo {42} > foo {43});
}
 
// This code produces the following output :
//
// ffoo {42}.compare_to(foo {42}) = 0
// foo {42}.compare_to(foo {41}) = 1
// foo {42}.compare_to(foo {43}) = -1
//
// foo {42} <=> foo {42} = equivalent
// foo {42} <=> foo {41} = greater
// foo {42} <=> foo {43} = less
//
// foo {42} <= foo {42} = true
// foo {42} <= foo {41} = false
// foo {42} <= foo {43} = true
//
// foo {42} < foo {42} = false
// foo {42} < foo {41} = false
// foo {42} < foo {43} = true
//
// foo {42} >= foo {42} = true
// foo {42} >= foo {41} = true
// foo {42} >= foo {43} = false
//
// foo {42} > foo {42} = false
// foo {42} > foo {41} = true
// foo {42} > foo {43} = false

Examples

generic_ienumerable2.cpp, generic_ienumerator.cpp, icomparable.cpp, ienumerable.cpp, ienumerator.cpp, and sprintf_class.cpp.

Public Methods
virtual int32	compare_to (const type_t &obj) const noexcept=0
	Compares the current instance with another object of the same type.

Member Function Documentation

compare_to()

template<typename type_t >

virtual int32 xtd::icomparable< type_t >::compare_to ( const type_t &  obj ) const

pure virtualnoexcept

Compares the current instance with another object of the same type.

Parameters

obj	An object to compare with this instance.

Returns

A 32-bit signed integer that indicates the relative order of the objects being compared. The return value has these meanings:

Value	Condition
Less than zero	This instance is less than obj.
Zero	This instance is equal to obj.
Greater than zero	This instance is greater than obj.

Implemented in xtd::any_object, xtd::box< type_t >, xtd::date_time, xtd::guid, xtd::time_span, xtd::time_zone_info, and xtd::version.

---

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

• xtd.core/include/xtd/icomparable.h