Q132165: FIX: Non-const Conversion Operators Allowed on const Object

Article: Q132165
Product(s): Microsoft C Compiler
Version(s): 1.0,1.5,1.51,1.52,2.0,2.1,2.20
Operating System(s): 
Keyword(s): kbbuglist kbfixlist
Last Modified: 29-JUL-2001

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The information in this article applies to:

- Microsoft C/C++ Compiler (CL.EXE), included with:
   - Microsoft C/C++ for MS-DOS, version 7.0 
   - Microsoft Visual C++, versions 1.0, 1.5, 1.51, 1.52 
   - *EDITOR Please do not choose this product*Microsoft Visual C++ 32-bit Edition* use 241, 265, 225, versions 1.0, 2.0, 2.1, 2.20 
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SYMPTOMS
========

Visual C++ illegally allows use of non-const member functions with const
objects. Because of this, const data could be modified.

Visual C++ correctly generates errors in most situations where non-const member
functions are used on const objects, but fails to generate errors in the case of
non-const conversion operators.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug was corrected in Microsoft Visual C++,
32-bit Edition, version 4.0.

MORE INFORMATION
================

The sample code should generate this error message:

  error C2664: 'x_t::x_t(const struct x_t&)' : cannot convert parameter 1
  from 'struct x_t*const ' to 'const struct x_t&'

Sample Code to Reproduce Problem
--------------------------------

  /* Compile options needed: none
  */ 
  struct x_t {
    int i;
    operator int() {return i;}
  };

  void func(const x_t& x)
  {
      int j = (int)x;     //C2664 should be generated on this line
  }

Additional query words: 1.00 2.00 2.10 2.20 7.00 8.00 8.00c 9.00 9.10

======================================================================
Keywords          :  kbbuglist kbfixlist
Technology        : kbVCsearch kbAudDeveloper kbCVCComp
Version           : :1.0,1.5,1.51,1.52,2.0,2.1,2.20
Issue type        : kbbug
Solution Type     : kbfix

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