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Language Extensions
3.6 Standard C and standard C++ language extensions
The compiler supports numerous extensions to both the ISO C99 and the ISO C++
Standards, such as various integral type extensions, various floating-point extensions,
hexadecimal floating-point constants, and anonymous classes, structures, and unions.
These extensions are available if:
• the source language is C++ and you are compiling in non strict mode
• the source language is C99 and you are compiling in non strict mode
• the source language is C90 and you are compiling in non strict mode.
These extensions are not available if:
• the source language is C++ and the compiler is restricted to compiling strict C++
using the --strict compiler option.
• the source language is C99 and the compiler is restricted to compiling strict
Standard C using the --strict compiler option.
• the source language is C90 and the compiler is restricted to compiling strict C90
using the --strict compiler option.
3.6.1 Address of a register variable
The address of a variable with register storage class can be taken.
Errors
The compiler generates a warning if you take the address of a variable with register
storage class.
Example
void foo(void)
{
register int i;
int *j = &i;
}
3.6.2 Arguments to functions
Default arguments can be specified for function parameters other than those of a
top-level function declaration. For example, they are accepted on typedef declarations
and on pointer-to-function and pointer-to-member-function declarations.
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