cpp/string/basic string/clear - Revision history

Space Mission: /* Example */ `assert`=>`cout` for no-warranty case; {{ddcla}}

2024-10-18T21:58:37Z

Example: `assert`=>`cout` for no-warranty case; {{ddcla}}

← Older revision		Revision as of 21:58, 18 October 2024
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	{{cpp/string/basic_string/title\|clear}}		{{cpp/string/basic_string/title\|clear}}
	{{cpp/string/basic_string/navbar}}		{{cpp/string/basic_string/navbar}}
	{{~~ddcl~~\|~~notes~~=~~{{mark noexcept since~~ c++11~~}}<br>{{mark~~ constexpr ~~since~~ c++20}}\|1=		{{ddcla\|noexcept=c++11\|constexpr=c++20\|
	void clear();		void clear();
	}}		}}
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	\|code=		\|code=
	#include <cassert>		#include <cassert>
			#include <iostream>
	#include <string>		#include <string>

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	s.clear();		s.clear();
	~~assert(s.capacity() == capacity); // <- not guaranteed~~
	assert(s.empty());		assert(s.empty());
	assert(s.size() == 0);		assert(s.size() == 0);
			std::cout << std::boolalpha << (s.capacity() == capacity) << '\n';
	}		}
			\|p=true
	\|output=		\|output=
			true
	}}		}}

2024-04-18T20:37:01Z

Synopsis: noexcept/constexpr.

← Older revision		Revision as of 20:37, 18 April 2024
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	{{cpp/string/basic_string/title\|clear}}		{{cpp/string/basic_string/title\|clear}}
	{{cpp/string/basic_string/navbar}}		{{cpp/string/basic_string/navbar}}
	{{~~dcl begin~~}}		{{ddcl\|notes={{mark noexcept since c++11}}<br>{{mark constexpr since c++20}}\|1=
	{{~~dcl rev multi\|until1=~~c++11\|~~dcl1~~=
	void clear();		void clear();
	~~\|until2=c++20\|dcl2=~~
	~~void clear() noexcept;~~
	~~\|dcl3=~~
	~~constexpr void clear() noexcept;~~
	}}		}}
	~~{{dcl end}}~~

	Removes all characters from the string as if by executing {{c\|erase(begin(), end())}}.		Removes all characters from the string as if by executing {{c\|erase(begin(), end())}}.

2023-05-31T17:29:01Z

fmt

← Older revision		Revision as of 17:29, 31 May 2023
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	{{cpp/string/basic_string/title \| clear}}		{{cpp/string/basic_string/title\|clear}}
	{{cpp/string/basic_string/navbar}}		{{cpp/string/basic_string/navbar}}
	{{dcl begin}}		{{dcl begin}}
	{{dcl rev multi \| until1=c++11 \| dcl1=		{{dcl rev multi\|until1=c++11\|dcl1=
	void clear();		void clear();
	\| until2=c++20 \| dcl2=		\|until2=c++20\|dcl2=
	void clear() noexcept;		void clear() noexcept;
	\| dcl3=		\|dcl3=
	constexpr void clear() noexcept;		constexpr void clear() noexcept;
	}}		}}
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	int main()		int main()
	{		{
	std::string s{ "Exemplar" };		std::string s{"Exemplar"};
	std::string::size_type const capacity = s.capacity();		std::string::size_type const capacity = s.capacity();

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	===See also===		===See also===
	{{dsc begin}}		{{dsc begin}}
	{{dsc inc \| cpp/string/basic_string/dsc erase}}		{{dsc inc\|cpp/string/basic_string/dsc erase}}
	{{dsc end}}		{{dsc end}}

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

2021-11-08T17:36:09Z

Added comment to capacity assertion that the behavior is not guaranteed

← Older revision		Revision as of 17:36, 8 November 2021
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	s.clear();		s.clear();
	assert(s.capacity() == capacity);		assert(s.capacity() == capacity); // <- not guaranteed
	assert(s.empty());		assert(s.empty());
	assert(s.size() == 0);		assert(s.size() == 0);

2020-02-18T07:46:18Z

P0980R1

← Older revision		Revision as of 07:46, 18 February 2020
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	{{dcl rev multi \| until1=c++11 \| dcl1=		{{dcl rev multi \| until1=c++11 \| dcl1=
	void clear();		void clear();
	\| dcl2=		\| until2=c++20 \| dcl2=
	void clear() noexcept;		void clear() noexcept;
			\| dcl3=
			constexpr void clear() noexcept;
	}}		}}
	{{dcl end}}		{{dcl end}}

2019-03-29T10:53:00Z

merge noexcept

← Older revision		Revision as of 10:53, 29 March 2019
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	{{cpp/string/basic_string/navbar}}		{{cpp/string/basic_string/navbar}}
	{{dcl begin}}		{{dcl begin}}
	{{dcl \|		{{dcl rev multi \| until1=c++11 \| dcl1=
	void clear();		void clear();
			\| dcl2=
			void clear() noexcept;
	}}		}}
	{{dcl end}}		{{dcl end}}
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	===Notes===		===Notes===
	Unlike for {{lc\|std::vector::clear}}, the C++ standard does not explicitly require that {{lc\|capacity}} is unchanged by this function, but existing implementations do not change capacity. This means that they do not release the allocated memory (see also {{lc\|shrink_to_fit}}).		Unlike for {{lc\|std::vector::clear}}, the C++ standard does not explicitly require that {{lc\|capacity}} is unchanged by this function, but existing implementations do not change capacity. This means that they do not release the allocated memory (see also {{lc\|shrink_to_fit}}).

	~~===Exceptions===~~
	~~{{rev begin}}~~
	~~{{rev \| until=c++11 \| (none) }}~~
	~~{{rev \| since=c++11 \| {{unreviewed noexcept}} }}~~
	~~{{rev end}}~~

	===Complexity===		===Complexity===
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	{{dsc end}}		{{dsc end}}

	[[de~~:cpp/string/basic string/clear]]~~		{{langlinks\|de\|es\|fr\|it\|ja\|pl\|pt\|ru\|zh}}
	[[es~~:cpp/string/basic string/clear]]~~
	[[fr~~:cpp/string/basic string/clear]]~~
	[[it~~:cpp/string/basic string/clear]]~~
	[[ja~~:cpp/string/basic string/clear]]~~
	[[pl~~:cpp/string/basic string/clear]]~~
	[[pt~~:cpp/string/basic string/clear]]~~
	[[ru~~:cpp/string/basic string/clear]]~~
	[[zh~~:cpp/string/basic string/clear]]~~

2018-02-11T04:12:16Z

Undo/edit ("Effects:" clause is normative; the spec says complexity is linear, but indeed it's probably with noting implementation detail)

← Older revision		Revision as of 04:12, 11 February 2018
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	===Complexity===		===Complexity===
	~~Not specified. Most~~ implementations operate in constant time~~; they don't actually call {{c\|erase(begin(), end())}}~~.		Linear in the size of the string, although existing implementations operate in constant time.

	===Example===		===Example===

2018-02-09T10:08:16Z

Complexity is not necessarily linear.

← Older revision		Revision as of 10:08, 9 February 2018
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	===Complexity===		===Complexity===
	~~Linear~~ in ~~the size of the string~~.		Not specified. Most implementations operate in constant time; they don't actually call {{c\|erase(begin(), end())}}.

	===Example===		===Example===

2017-07-03T12:25:37Z

Unqualify the link to shrink_to_fit

← Older revision		Revision as of 12:25, 3 July 2017
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	===Notes===		===Notes===
	Unlike for {{lc\|std::vector::clear}}, the C++ standard does not explicitly require that {{lc\|capacity}} is unchanged by this function, but existing implementations do not change capacity. This means that they do not release the allocated memory (see also {{lc\|~~std::basic_string::~~shrink_to_fit}}).		Unlike for {{lc\|std::vector::clear}}, the C++ standard does not explicitly require that {{lc\|capacity}} is unchanged by this function, but existing implementations do not change capacity. This means that they do not release the allocated memory (see also {{lc\|shrink_to_fit}}).

	===Exceptions===		===Exceptions===

2017-07-03T12:24:08Z

Add a link to shrink_to_fit

← Older revision		Revision as of 12:24, 3 July 2017
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	===Notes===		===Notes===
	Unlike for {{lc\|std::vector::clear}}, the C++ standard does not explicitly require that {{lc\|capacity}} is unchanged by this function, but existing implementations do not change capacity.		Unlike for {{lc\|std::vector::clear}}, the C++ standard does not explicitly require that {{lc\|capacity}} is unchanged by this function, but existing implementations do not change capacity. This means that they do not release the allocated memory (see also {{lc\|std::basic_string::shrink_to_fit}}).

	===Exceptions===		===Exceptions===