cpp/string/basic string/swap - Revision history

D41D8CD98F: fix

2025-04-02T01:01:42Z

fix

← Older revision		Revision as of 01:01, 2 April 2025
Line 13:		Line 13:

	{{rrev\|since=c++11\|		{{rrev\|since=c++11\|
	If {{c ~~multi~~\|std::allocator_traits<~~Allocator~~>::\| propagate_on_container_swap::value &&\|~~get_allocator()~~ {{==}} s.~~get_allocator~~(~~)}} is~~ {{c\|~~false~~}}, the behavior is undefined.		If {{c\|std::allocator_traits<allocator_type>::propagate_on_container_swap::value}} is {{c\|true}}, then the allocators are exchanged using an unqualified call to non-member {{tt\|swap}}. Otherwise, they are not swapped (and if {{c\|1=get_allocator() != other.get_allocator()}}, the behavior is undefined).}}
	}}

	===Parameters===		===Parameters===

Xmcgcg: Added LWG issue #2151 DR.

2024-10-16T06:55:39Z

Added LWG issue #2151 DR.

← Older revision		Revision as of 06:55, 16 October 2024
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	{{rrev\|since=c++11\|		{{rrev\|since=c++11\|
	{{~~anchor~~\|~~ub}}~~		If {{c multi\|std::allocator_traits<Allocator>::\| propagate_on_container_swap::value &&\|get_allocator() {{==}} s.get_allocator()}} is {{c\|false}}, the behavior is undefined.
	~~The behavior is undefined if~~ {{~~tt\|Allocator~~}} ~~does not propagate on swap and the allocators of {{c\|*this~~}} ~~and~~ {{c\|~~other~~}} ~~are unequal~~.
	}}		}}

Line 21:		Line 20:
	{{par\|other\|string to exchange the contents with}}		{{par\|other\|string to exchange the contents with}}
	{{par end}}		{{par end}}

	~~===Return value===~~
	~~(none)~~

	===Complexity===		===Complexity===
Line 34:		Line 30:
	}}		}}
	{{rev\|since=c++11\|		{{rev\|since=c++11\|
	~~Exceptions can only be~~ thrown ~~in the case where~~ the behavior is undefined ~~(see [[#ub\|above]])~~.		No exception is thrown, unless the behavior is undefined.

	{{cpp/strong exception safety guarantee}}		{{cpp/strong exception safety guarantee}}
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	{{dr list item\|wg=lwg\|dr=403\|std=C++98\|before={{tt\|swap()}} might throw an exception\|after=no exception is thrown}}		{{dr list item\|wg=lwg\|dr=403\|std=C++98\|before={{tt\|swap()}} might throw an exception\|after=no exception is thrown}}
	{{dr list item\|wg=lwg\|dr=535\|std=C++98\|before=swapping strings did not preserve the character orders\|after=orders are also preserved}}		{{dr list item\|wg=lwg\|dr=535\|std=C++98\|before=swapping strings did not preserve the character orders\|after=orders are also preserved}}
			{{dr list item\|wg=lwg\|dr=2151\|paper=P1148R0\|std=C++11\|before=no exception was thrown in the case<br>of unequal non-propagating allocators\|after=the behavior is<br>undefined in this case}}
	{{dr list end}}		{{dr list end}}

Space Mission: /* Synopsis */ +constexpr since

2024-04-21T19:12:33Z

Synopsis: +constexpr since

← Older revision		Revision as of 19:12, 21 April 2024
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	\|until1=c++17\|dcl1=		\|until1=c++17\|dcl1=
	void swap( basic_string& other );		void swap( basic_string& other );
	\|~~until2~~=c++20\|dcl2=		\|notes2={{mark constexpr since c++20}}\|dcl2=
	void swap( basic_string& other ) noexcept(/* see below */);		void swap( basic_string& other ) noexcept(/* see below */);
	~~\|dcl3=~~
	~~constexpr void swap( basic_string& other ) noexcept(/* see below */);~~
	}}		}}
	{{dcl end}}		{{dcl end}}

Xmcgcg: Added strong exception safety guarantee.

2023-07-12T09:37:54Z

Added strong exception safety guarantee.

← Older revision		Revision as of 09:37, 12 July 2023
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	===Exceptions===		===Exceptions===
	No exception is thrown{{rev ~~inl~~\|since=c++11\|~~, except~~ in the case where the behavior is undefined (see [[#ub\|above]])}}.		{{rev begin}}
			{{rev\|until=c++11\|
			No exception is thrown.
			}}
			{{rev\|since=c++11\|
			Exceptions can only be thrown in the case where the behavior is undefined (see [[#ub\|above]]).

			{{cpp/strong exception safety guarantee}}
			}}
			{{rev end}}


	{{rrev\|since=c++17\|		{{rrev\|since=c++17\|

Andreas Krug: headers sorted

2023-06-03T07:56:47Z

headers sorted

← Older revision		Revision as of 07:56, 3 June 2023
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	{{example		{{example
	\|code=		\|code=
			#include <iostream>
	#include <string>		#include <string>
	~~#include <iostream>~~

	int main()		int main()

Xmcgcg: Added LWG issue #535 DR.

2023-02-23T02:49:09Z

Added LWG issue #535 DR.

← Older revision		Revision as of 02:49, 23 February 2023
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	std::string a = "AAA";		std::string a = "AAA";
	std::string b = "BBBB";		std::string b = "BBBB";

	std::cout << "Before swap:\n"		std::cout << "Before swap:\n"
	"a = " << a << "\n"		"a = " << a << "\n"
	"b = " << b << "\n\n";		"b = " << b << "\n\n";

	a.swap(b);		a.swap(b);

	std::cout << "After swap:\n"		std::cout << "After swap:\n"
	"a = " << a << "\n"		"a = " << a << "\n"
Line 72:		Line 72:
	{{dr list begin}}		{{dr list begin}}
	{{dr list item\|wg=lwg\|dr=403\|std=C++98\|before={{tt\|swap()}} might throw an exception\|after=no exception is thrown}}		{{dr list item\|wg=lwg\|dr=403\|std=C++98\|before={{tt\|swap()}} might throw an exception\|after=no exception is thrown}}
			{{dr list item\|wg=lwg\|dr=535\|std=C++98\|before=swapping strings did not preserve the character orders\|after=orders are also preserved}}
	{{dr list end}}		{{dr list end}}

Space Mission: fmt.

2023-02-07T11:41:38Z

fmt.

← Older revision		Revision as of 11:41, 7 February 2023
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	{{rrev\|since=c++17\|		{{rrev\|since=c++17\|
	{{noexcept\|std::allocator_traits<Allocator>::propagate_on_container_swap::value		{{noexcept\|std::allocator_traits<Allocator>::propagate_on_container_swap::value {{!!}}
	{{!!}} std::allocator_traits<Allocator>::is_always_equal::value}}		std::allocator_traits<Allocator>::is_always_equal::value}}
	}}		}}

Line 47:		Line 47:
	{		{
	std::string a = "AAA";		std::string a = "AAA";
	std::string b = "~~BBB~~";		std::string b = "BBBB";

	std::cout << "~~before~~ swap~~" << '~~\n';		std::cout << "Before swap:\n"
	~~std::cout <<~~ "a: " << a << '\n';		"a = " << a << "\n"
	~~std::cout <<~~ "b: " << b << '\n';		"b = " << b << "\n\n";

	a.swap(b);		a.swap(b);

	std::cout << "~~after~~ swap~~" << '~~\n';		std::cout << "After swap:\n"
	~~std::cout <<~~ "a: " << a << '\n';		"a = " << a << "\n"
	~~std::cout <<~~ "b: " << b << '\n';		"b = " << b << '\n';
	}		}
	\|output=		\|output=
	~~before~~ swap		Before swap:
	a: AAA		a = AAA
	b~~: BBB~~		b = BBBB
	~~after~~ swap
	a~~: BBB~~		After swap:
	b: AAA		a = BBBB
			b = AAA
	}}		}}

Xmcgcg: Added LWG issue #403 DR.

2023-02-07T09:38:22Z

Added LWG issue #403 DR.

← Older revision		Revision as of 09:38, 7 February 2023
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	{{cpp/string/basic_string/title \| swap}}		{{cpp/string/basic_string/title\|swap}}
	{{cpp/string/basic_string/navbar}}		{{cpp/string/basic_string/navbar}}
	{{dcl begin}}		{{dcl begin}}
	{{dcl rev multi		{{dcl rev multi
	\| until1=c++17 \| dcl1=		\|until1=c++17\|dcl1=
	void swap( basic_string& other );		void swap( basic_string& other );
	\| until2=c++20 \| dcl2=		\|until2=c++20\|dcl2=
	void swap( basic_string& other ) noexcept(/* see below */);		void swap( basic_string& other ) noexcept(/* see below */);
	\| dcl3=		\|dcl3=
	constexpr void swap( basic_string& other ) noexcept(/* see below */);		constexpr void swap( basic_string& other ) noexcept(/* see below */);
	}}		}}
	{{dcl end}}		{{dcl end}}

	Exchanges the contents of the string with those of {{tt\|other}}. All iterators and references may be invalidated.		Exchanges the contents of the string with those of {{c\|other}}. All iterators and references may be invalidated.

	{{rrev\|since=c++11\|		{{rrev\|since=c++11\|
	The behavior is undefined if {{tt\|Allocator}} does not propagate on swap and the allocators of {{tt\|*this}} and {{tt\|other}} are unequal.		{{anchor\|ub}}
			The behavior is undefined if {{tt\|Allocator}} does not propagate on swap and the allocators of {{c\|*this}} and {{c\|other}} are unequal.
	}}		}}

	===Parameters===		===Parameters===
	{{par begin}}		{{par begin}}
	{{par \| other \| string to exchange the contents with}}		{{par\|other\|string to exchange the contents with}}
	{{par end}}		{{par end}}

Line 28:		Line 29:
	===Complexity===		===Complexity===
	Constant.		Constant.

			===Exceptions===
			No exception is thrown{{rev inl\|since=c++11\|, except in the case where the behavior is undefined (see [[#ub\|above]])}}.

	{{rrev\|since=c++17\|		{{rrev\|since=c++17\|
	~~===Exceptions===~~
	{{noexcept\|std::allocator_traits<Allocator>::propagate_on_container_swap::value		{{noexcept\|std::allocator_traits<Allocator>::propagate_on_container_swap::value
	{{!!}} std::allocator_traits<Allocator>::is_always_equal::value}}		{{!!}} std::allocator_traits<Allocator>::is_always_equal::value}}
Line 37:		Line 40:
	===Example===		===Example===
	{{example		{{example
	\| code=		\|code=
	#include <string>		#include <string>
	#include <iostream>		#include <iostream>
Line 45:		Line 48:
	std::string a = "AAA";		std::string a = "AAA";
	std::string b = "BBB";		std::string b = "BBB";

	std::cout << "before swap" << '\n';		std::cout << "before swap" << '\n';
	std::cout << "a: " << a << '\n';		std::cout << "a: " << a << '\n';
	std::cout << "b: " << b << '\n';		std::cout << "b: " << b << '\n';

	a.swap(b);		a.swap(b);

	std::cout << "after swap" << '\n';		std::cout << "after swap" << '\n';
	std::cout << "a: " << a << '\n';		std::cout << "a: " << a << '\n';
	std::cout << "b: " << b << '\n';		std::cout << "b: " << b << '\n';
	}		}
			\|output=
	\| output=
	before swap		before swap
	a: AAA		a: AAA
Line 65:		Line 67:
	b: AAA		b: AAA
	}}		}}

			===Defect reports===
			{{dr list begin}}
			{{dr list item\|wg=lwg\|dr=403\|std=C++98\|before={{tt\|swap()}} might throw an exception\|after=no exception is thrown}}
			{{dr list end}}

	===See also===		===See also===
	{{dsc begin}}		{{dsc begin}}
	{{dsc inc \| cpp/algorithm/dsc swap}}		{{dsc inc\|cpp/algorithm/dsc swap}}
	{{dsc inc \| cpp/algorithm/dsc swap_ranges}}		{{dsc inc\|cpp/algorithm/dsc swap_ranges}}
	{{dsc inc \| cpp/string/basic_string_view/dsc {{SUBPAGENAMEE}}}}		{{dsc inc\|cpp/string/basic_string_view/dsc {{SUBPAGENAMEE}}}}
	{{dsc end}}		{{dsc end}}

	{{langlinks\|de\|es\|fr\|it\|ja\|pt\|ru\|zh}}		{{langlinks\|de\|es\|fr\|it\|ja\|pt\|ru\|zh}}

Space Mission: /* See also */ +

2021-05-04T12:24:08Z

Fruderica: reorder

2020-08-27T13:56:03Z

reorder

← Older revision		Revision as of 13:56, 27 August 2020
Line 26:		Line 26:
	(none)		(none)

	~~{{rev begin}}~~		===Complexity===
	{{~~rev~~\|since=c++17\|		Constant.

			{{rrev\|since=c++17\|
	===Exceptions===		===Exceptions===
	{{noexcept\|std::allocator_traits<Allocator>::propagate_on_container_swap::value		{{noexcept\|std::allocator_traits<Allocator>::propagate_on_container_swap::value
	{{!!}} std::allocator_traits<Allocator>::is_always_equal::value}}		{{!!}} std::allocator_traits<Allocator>::is_always_equal::value}}
	}}		}}
	~~{{rev end}}~~

	===Example===		===Example===
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	b: AAA		b: AAA
	}}		}}

	~~===Complexity===~~
	~~Constant.~~

	{{langlinks\|de\|es\|fr\|it\|ja\|pt\|ru\|zh}}		{{langlinks\|de\|es\|fr\|it\|ja\|pt\|ru\|zh}}

← Older revision		Revision as of 12:24, 4 May 2021
Line 65:		Line 65:
	b: AAA		b: AAA
	}}		}}

			===See also===
			{{dsc begin}}
			{{dsc inc \| cpp/algorithm/dsc swap}}
			{{dsc inc \| cpp/algorithm/dsc swap_ranges}}
			{{dsc inc \| cpp/string/basic_string_view/dsc {{SUBPAGENAMEE}}}}
			{{dsc end}}

	{{langlinks\|de\|es\|fr\|it\|ja\|pt\|ru\|zh}}		{{langlinks\|de\|es\|fr\|it\|ja\|pt\|ru\|zh}}