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Difference between revisions of "cpp/string/wide/wmemmove"

From cppreference.com
< cpp‎ | string‎ | wide
m (Update links.)
(fix wording (these are for arrays of wide chars, not any objects))
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}}
 
}}
  
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Copies {{tt|count}} wide characters from the object pointed to by {{tt|src}} to the object pointed to by {{tt|dest}}. The objects may overlap: copying takes place as if the characters were copied to a temporary character array and then the characters were copied from the array to {{tt|dest}}. If the objects are not trivially-copyable (scalars, arrays, C-style structs), the behavior is undefined.
+
Copies exactly {{tt|count}} successive wide characters from the wide character array pointed to by {{tt|src}} to the wide character array pointed to by {{tt|dest}}.
 +
 
 +
If {{tt|count}} is zero, the function does nothing.
 +
 
 +
The arrays may overlap: copying takes place as if the wide characters were copied to a temporary wide character array and then copied from the temporary array to {{tt|dest}}.
  
 
===Parameters===
 
===Parameters===
 
{{par begin}}
 
{{par begin}}
−
{{par | dest | pointer to the memory location to copy to}}
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{{par | dest | pointer to the wide character array to copy to}}
−
{{par | src | pointer to the memory location to copy from}}
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{{par | src | pointer to the wide character array to copy from}}
−
{{par | count | number of bytes to copy}}
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{{par | count | number of wide characters to copy}}
 
{{par end}}
 
{{par end}}
  
 
===Return value===
 
===Return value===
−
{{tt|dest}}
+
Returns a copy of {{tt|dest}}
 +
 
 +
===Notes===
 +
This function is not locale-sensitive and pays no attention to the values of the {{c|wchar_t}} objects it copies: nulls as well as invalid characters are copied too.
  
 
===Example===
 
===Example===
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  |
 
  |
 
  | code=
 
  | code=
−
| output=
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#include <iostream>
 +
#include <cwchar>
 +
#include <locale>
 +
#include <clocale>
 +
 
 +
int main()
 +
{
 +
    std::setlocale(LC_ALL, "en_US.utf8");
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    std::wcout.imbue(std::locale("en_US.utf8"));
 +
 
 +
    wchar_t str[] = L"αβγδεζηθικλμνξοπρστυφχψω";
 +
    std::wcout << str << '\n';
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    std::wmemmove(str+4, str+3, 3); // copy from [δεζ] to [εζη]
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    std::wcout << str << '\n';
 +
}
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|p=true
 +
| output=
 +
αβγδεζηθικλμνξοπρστυφχψω
 +
αβγδδεζθικλμνξοπρστυφχψω
 
}}
 
}}
  
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{{dsc begin}}
 
{{dsc begin}}
 
{{dsc inc | cpp/string/wide/dsc wmemcpy}}
 
{{dsc inc | cpp/string/wide/dsc wmemcpy}}
 +
{{dsc inc | cpp/string/byte/dsc memmove}}
 
{{dsc inc | cpp/algorithm/dsc copy}}
 
{{dsc inc | cpp/algorithm/dsc copy}}
 
{{dsc inc | cpp/algorithm/dsc copy_backward}}
 
{{dsc inc | cpp/algorithm/dsc copy_backward}}
−
{{dsc inc | cpp/types/dsc is_trivially_copyable}}
 
 
{{dsc see c | c/string/wide/wmemmove}}
 
{{dsc see c | c/string/wide/wmemmove}}
 
{{dsc end}}
 
{{dsc end}}

Revision as of 06:51, 26 February 2015

 
C++
 
Strings library
 
Null-terminated wide strings
 
Defined in header <cwchar>
wchar_t* wmemmove( wchar_t* dest, const wchar_t* src, std::size_t count );

Copies exactly count successive wide characters from the wide character array pointed to by src to the wide character array pointed to by dest.

If count is zero, the function does nothing.

The arrays may overlap: copying takes place as if the wide characters were copied to a temporary wide character array and then copied from the temporary array to dest.

Contents

Parameters

dest - pointer to the wide character array to copy to
src - pointer to the wide character array to copy from
count - number of wide characters to copy

Return value

Returns a copy of dest

Notes

This function is not locale-sensitive and pays no attention to the values of the wchar_t objects it copies: nulls as well as invalid characters are copied too.

Example

Run this code
#include <iostream>
#include <cwchar>
#include <locale>
#include <clocale>
 
int main()
{
    std::setlocale(LC_ALL, "en_US.utf8");
    std::wcout.imbue(std::locale("en_US.utf8"));
 
    wchar_t str[] = L"αβγδεζηθικλμνξοπρστυφχψω";
    std::wcout << str << '\n';
    std::wmemmove(str+4, str+3, 3); // copy from [δεζ] to [εζη]
    std::wcout << str << '\n';
}

Possible output: 

αβγδεζηθικλμνξοπρστυφχψω
αβγδδεζθικλμνξοπρστυφχψω

See also

 copies a certain amount of wide characters between two non-overlapping arrays
(function) [edit]
moves one buffer to another
(function) [edit]
(C++11)
 copies a range of elements to a new location
(function template) [edit]
copies a range of elements in backwards order
(function template) [edit]
C documentation for wmemmove
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