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c++scopedeclaration

C++ Warning if re-declaring member variable in function

Given a structure such as below

class A {
  int test;
  void f() { int test; }
}

I just had a curious case in which the code in f(), when referring to test, compiled under VS2010, correctly referred to the function local variable, however, when compiled under gcc, incorrectly referred to the member variable. Took me quite a while to track down.

Anyway, question is, is there an option in gcc or VS to enable compiler warnings every time a member variable is re-declared in a local function scope?

Solution

  • In GCC, -Wshadow. From the documentation:

    Warn whenever a local variable or type declaration shadows another variable, parameter, type, or class member (in C++), or whenever a built-in function is shadowed. Note that in C++, the compiler will not warn if a local variable shadows a struct/class/enum, but will warn if it shadows an explicit typedef.