Convert wchar_t to uint16

Question

Dear all,

I need to convert wchar_t to uint16 type and vice-versa. plz anyone help

Answer 1

>I need to convert wchar_t to uint16 type and vice-versa. plz anyone help

If on the platform you're using both are just 16-bit values, all you
will need is a cast.

Dave

Answer 2

Convert meaning what, exactly?  i.e. do you want to treat a single wchat_t object as a uint16?  If so, then just cast, as David suggests.

Or do you want to convert a string of wchar_t characters into a unit16 by parsing the text, e.g. to convert L"123" into the unit16 value 123?  If this is what you're looking for, check out _wtoi and similar functions for the wchar-to-uint conversion, and _itow and similar functions for the unit to wchar conversion.  If you're using the C++ standard library, you can accomplish both conversions using std::basic_stringstream (particularly the typdefs wistringstream and wostringstream).

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-cd Mark the best replies as answers!

Answer 3

I am developing a project (for both windows and MAC OS) that uses xerces for xml manipulation. So in windows I had no problem since XMLCh is the typedef of wchar_t. But whereas in LINUX/MACOS platform, XMLCh is the typedef of uint16_t. I have used wchar_t in many places in my project. So there I could pass in a string (eg. L"HAI this is for testing") and getback it with no change. But in LINUX/MAC OS how to convert the same wstring (L"HAI this is for testing") to uint16_t* and again getback the string from uint16_t* to wchar_t* with no change in string.

Answer 4

I am developing a project (for both windows and MAC OS) that uses xerces for xml manipulation. So in windows I had no problem since XMLCh is the typedef of wchar_t. But whereas in LINUX/MACOS platform, XMLCh is the typedef of uint16_t. I have used wchar_t in many places in my project. So there I could pass in a string (eg. L"HAI this is for testing") and getback it with no change. But in LINUX/MAC OS how to convert the same wstring (L"HAI this is for testing") to uint16_t* and again getback the string from uint16_t* to wchar_t* with no change in string.

Converting uint16_t* to wchar_t* is not the same as conveting uint16_t to wchar_t.
 
uint16_t and wchar_t are both integer types, so you should be able to convert between them using static_cast(), even if they are not the same size (provided of course that the value in question fits in the target representation).
 
Converting uint16_t* to wchar_t* will require a reinterpret_cast() (or C cast), and will only work if both are the same size on your platform. If they are not the same size, then you will need to convert each character.
 
Is wchar_t not 16 bits on Mac/Linux?
 

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David Wilkinson | Visual C++ MVP

Answer 5

davewilk [MVP] wrote:

Is wchar_t not 16 bits on Mac/Linux?

It's not. For reasons I could never understand, GCC chose to make  wchar_t 32 bits, with UTF-32 in mind. Pretty much every major library  that deals with Unicode strings defines its own wide char type as  unsigned short, because of this.

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Igor Tandetnik

Answer 6

Prabas08 wrote:

I am developing a project (for both windows and MAC OS) that uses  xerces for xml manipulation. So in windows I had no problem
since*XMLCh* is the typedef of wchar_t.But whereas in LINUX/MACOS  platform, *XMLCh *is the typedef ofuint16_t. I have used
wchar_tin many places in my project. So there I could pass in a string  (eg. L"HAI this is for testing") and getback it with no
change. But in LINUX/MAC OS how to convert the samewstring (*L"HAI  this is for testing"*) touint16_t* and again getback the
string from uint16_t* to wchar_t* with no change in string.   

If I recall correctly (it's been more than 10 years), with Xerces-C you  are supposed so use XMLString::transcode("HAI") (and then later  XMLString::release on the returned buffer). You can't use wchar_t or  L"string", since GCC defines wchar_t as 32-bit large, while Xerces-C  does everything in UTF-16.

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Igor Tandetnik