why a macro defined as member function cant access the private data.

[vishnu123]

Hi All,

why a macro defined as member function cant access the private data.

class A
{
int x;
public:
#define func(x,y) x=y; //why error
}

[MiiNiPaa]

Defines are not the part of the lanuage in any way. It is just a method to tell preprocessor (not the compiler!) to replace all entries of func(x, y) by x=y. You can replace them manually and see what it would look like. Only after replacing everything, file would be sent to the compiler.

[Peter87]

Macros are expanded before compilation starts so they doesn't care about scope or anything. It doesn't matter where you define it. It's just dumb text replace feature.

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#include <iostream> class A { int x; public: #define func(x,y) x=y; }; int main() { int a = 1; int b = 2; func(a, b); // This will be replaced by a=b; before the compilation starts. std::cout << a << ' ' << b << std::endl; }

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