Member function [c++] definition not found by VS2015 due to #define - c++

Question

Have a #define which is called within a member function. By this #define the member-function definition isn't found by the VS2015 environment at the declaration level. The project compiles and runs just fine so no problem there.
This does however, break the functionality of VS2015 to jump between the declaration and definition.
It can be solved by writing the #define within the source, but can this be solved without removing the #define?
File: cFoo.h
class cFoo
{
public:
int Bits;
void Member();
}
File: cFoo.cpp
#include "cFoo.h"
#define SWITCH( x ) for ( int bit = 1; x >= bit; bit *= 2) if (x & bit) switch (bit)
void cFoo::Member()
{
SWITCH( Bits )
{
case 1: break;
case 2: break;
default: break;
}
}

Answer 1

I would disadvice to use such constructs. It is rather counterintuitive and difficult to understand.
Possible problems/difficulties:
switch case with breaks suggests that only one case is executed, but your macro logic hides the loop.
the default case is executed multiple times depending on the highest populated bit.
using signed int as bit set -> use unsigned - its less prone to implementation defined behavior
it is possibly slow because of loop (I do not know if the compiler is able to unroll and optimize it)
its called SWITCH_BITS which suggests that bit numbers are expected, but cases have to be powers of two.
Your whole statement is not more compact than a simple if sequence.
if(bits & 1 ){
}
if(bits & 1024){
}
but you maybe want to test to bit numbers:
inline bool isBitSet(u32 i_bitset, u32 i_bit){ return i_bitset & (1 << i_bit);}
if(isBitSet(bits, 0){
}
if(isBitSet(bits, 10){
}

Answer 2

You can try doing this by completing the switch statement within the #define - macro:
Foo.h
#ifndef FOO_H
#define FOO_H
#ifndef SWITCH
#define SWITCH(x) \
do { \
for ( int bit = 1; (x) >= bit; bit *=2 ) { \
if ( (x) & bit ) { \
switch( bit ) { \
case 0: break; \
case 1: break; \
default: break; \
} \
} \
} \
} while(0)
#endif
class Foo {
public:
int Bits;
void Member();
};
#endif // !FOO_H
Foo.cpp
#include "Foo.h"
void Foo::Member() {
SWITCH( this->Bits );
}
When I was trying the #define or macro as you had it, Foo::Member()
was not being defined by intellisense...
However even with it not being defined I was able to build, compile and run it like this:
#ifndef SWITCH_A
#define SWITCH_A(x) \
for ( int bit = 1; (x) >= bit; bit *= 2 ) \
if ( (x) & bit ) \
switch (bit)
#endif
For some reason; MS Visual Studio was being very picky with it; meaning that I was having a hard time getting it to compile; it was even complaining about the "spacing" giving me compiler errors of missing { or ; need before... etc. Once I got all the spacing down properly it did eventually compile & run, but intellisense was not able to see that Foo::Member() was defined. When I tried it in the original manner that I've shown above; intellisense had no problem seeing that Foo::Member() was defined. Don't know if it's a pre-compiler bug, MS Visual Studio bug etc.; Just hope that this helps you.