Style question - using LPCTSTR as a pointer

[gw7rib]

I'm using a system in which TCHAR is typedef-ed to represent a
character, in this case a wchar_t to hold Unicode characters, and
LPCTSTR is typedef-ed to be a pointer to constant wchar_t. I presume
it's supposed to be a pointer to constant TCHAR, though they seem to
be defined in parallel rather than one typedef using the other.

I'm perfectly happy using LPCTSTR for a constant string, but for some
reason it seems odd to use LPCTSTR as an actual pointer. For instance,
in the following snippet:

for(ptr = str; *ptr; ptr++)

I am happy for str to be a LPCTSTR, but ptr feels like it should be a
const TCHAR*. Even though they are of course the same type.

Am I just weird?

Paul.

 

[Angus]

TCHAR is a wchar_t if UNICODE is defined. Otherwise it is a plain char.

LPCTSTR is Microsoft nonsense stuff. You can use eg const TCHAR* etc.

Of course, using std::string is much safer.

 

[Pavel]

I'm using a system in which TCHAR is typedef-ed to represent a
character, in this case a wchar_t to hold Unicode characters, and
LPCTSTR is typedef-ed to be a pointer to constant wchar_t. I presume
it's supposed to be a pointer to constant TCHAR, though they seem to
be defined in parallel rather than one typedef using the other.

I'm perfectly happy using LPCTSTR for a constant string, but for some
reason it seems odd to use LPCTSTR as an actual pointer. For instance,
in the following snippet:

for(ptr = str; *ptr; ptr++)

I am happy for str to be a LPCTSTR, but ptr feels like it should be a
const TCHAR*. Even though they are of course the same type.

Am I just weird?

Paul.

It's a microsoft-specific quite, but the answer could be that TCHAR
under UNICODE is defined to WCHAR, not wchar_t and WCHAR is *not
always* same as wchar_t. See
http://msdn.microsoft.com/en-us/library/ms684497(VS.85).aspx for the
details.

In the future for the problems like this I advice you to pre-process
your code and look into the output of the pre-processor to get a
definitive answer on what the identifiers you use really mean.

Hope this will help,
-Pavel

 

[James Kanze]

TCHAR is a wchar_t if UNICODE is defined. Otherwise it is a
plain char.

LPCTSTR is Microsoft nonsense stuff. You can use eg const
TCHAR* etc.

Of course, using std::string is much safer.

Or in his case, std::wstring.

FWIW: the whole idea of typedef'ing the character type seems a
bit wrong, somehow. Unless it is something along the lines:
typedef int32_t UTF32Char ;
typedef uint8_t UTF8Byte ;
etc. The idea that you can switch between wide characters and
narrow just by changing a typedef is simply wrong; in practice,
your code must know the actual type, and even the actual
encoding, in order to work.