check_signedness
Method deprecated or moved
This method is deprecated or moved on the latest stable version. The last existing version (v1_9_3_392) is shown here.
check_signedness(type, headers = nil, opts = nil, &b)Returns the signedness of the given type . You may optionally specify additional headers to search in for the type .
If the type is found and is a numeric type, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with ‘SIGNEDNESS_OF_’, followed by the type name, followed by ‘=X’ where ‘X’ is positive integer if the type is unsigned, or negative integer if the type is signed.
For example, if size_t is defined as unsigned, then check_signedness(‘size_t’) would returned +1 and the SIGNEDNESS_OF_SIZE_T=+1 preprocessor macro would be passed to the compiler, and SIGNEDNESS_OF_INT=-1 if check_signedness(‘int’) is done.
# File lib/mkmf.rb, line 1178
def check_signedness(type, headers = nil, opts = nil, &b)
typedef, member, prelude = typedef_expr(type, headers)
signed = nil
checking_for("signedness of #{type}", STRING_OR_FAILED_FORMAT) do
signed = try_signedness(typedef, member, [prelude], opts, &b) or next nil
$defs.push("-DSIGNEDNESS_OF_%s=%+d" % [type.tr_cpp, signed])
signed < 0 ? "signed" : "unsigned"
end
signed
end