[Bug c++/25689] missed diagnostic about assignment used as truth value.

[manu at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25689

Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2006-01-06 12:32:23         |2014-10-12

--- Comment #2 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
A simpler testcase:

struct Var {
  operator int() const;
  Var& operator = (int);
};

void foo(Var var)
{
  if (var = 0) {}  // we should warn
  if (var.operator=(0)) {} // we should NOT warn
}

Clang prints:

pr25689.C:8:11: warning: using the result of an assignment as a condition
without parentheses [-Wparentheses]
  if (var = 0) {}  // if (var.operator=(0))
      ~~~~^~~
pr25689.C:8:11: note: place parentheses around the assignment to silence this
warning
  if (var = 0) {}  // if (var.operator=(0))
          ^
      (      )
pr25689.C:8:11: note: use '==' to turn this assignment into an equality
comparison
  if (var = 0) {}  // if (var.operator=(0))
          ^
          ==