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Byte I/O

I'm trying to read a binary file, but the read() function in fstream takes
char*. What I really want are unsigned chars. How can I do this?

Thanks,

--Brian

Jul 19 '05 #1
2 2036
Brian wrote:
I'm trying to read a binary file, but the read() function in fstream
takes char*. What I really want are unsigned chars. How can I do
this?


fstream is just a typedef for basic_fstream<char>, i.e. a char based
stream. Read() takes a pointer to the stream's template argument type.
So if you create your file as basic_fstream<unsigned char>, read() will
take an unsigned char*.

Jul 19 '05 #2
Rolf Magnus <ra******@t-online.de> writes:
Brian wrote:
I'm trying to read a binary file, but the read() function in fstream
takes char*. What I really want are unsigned chars. How can I do
this?


fstream is just a typedef for basic_fstream<char>, i.e. a char based
stream. Read() takes a pointer to the stream's template argument type.
So if you create your file as basic_fstream<unsigned char>, read() will
take an unsigned char*.


AIUI, you would then also have to define a specialization of
char_traits<> for unsigned char, as that is not defined by the Standard.

Another common practice seems to be to use
reinterpret_cast<char *>() on a pointer into a buffer of unsigned
char.

--
Micah J. Cowan
mi***@cowan.name
Jul 19 '05 #3

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