"Function Types"

Hi,

$4.3 talks about conversion of functions to pointers, specifically "An
lvalue of function type T...". My idea of "function type" is based on
the following article from Herb "http://www.ddj.com/cpp/184401824".

I wrote the following small piece of code.


// CODE SNIPPET 1
int *fn(int *p, const char& rc){return (int *)0;}

typedef int* MYFUNCTIONTYPE(int *, const char&);

void invoke(MYFUNCTIONTYPE t){
	(t)(0, 'A');
}

void invoke(MYFUNCTIONTYPE *t){
	(*t)(0, 'A');
}

int main(){
	invoke(fn);
}

This code is ill-formed because the two versions of invoke are not
sufficiently different to be overloaded as complained by VS2008 and
Comeau.

However a slight modification to use typedef of function pointer,
makes the code perfectly well-formed as expected with the call
resolved to the first version of invoke.


// CODE SNIPPET 2
int *fn(int *p, const char& rc){return (int *)0;}

typedef int* (*MYFUNCTIONTYPE)(int *, const char&);         // Changed
to typedef of Function Pointer Type

void invoke(MYFUNCTIONTYPE t){
	(t)(0, 'A');
}

void invoke(MYFUNCTIONTYPE *t){
	(*t)(0, 'A');
}

int main(){
	invoke(fn);
}

So, basically I have two doubts:

a) Why is the first piece of code giving error?

b) $4.3- Does this section talk about the "function type" as in "CODE
SNIPPET 1" or as a more generic term and as interpreted in "CODE
SNIPPET 2"?

Regards,
Dabs

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