ChangesMeaningOf

ChangesMeaningOf is an error message from GnuCpp which arose when changes after version 4.1.2 broke code which had previously worked. This is best illustrated with an example. I came across this while working with BoostFusion. -- JohnFletcher

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Example code

 namespace Z {
   template <typename T> struct A { };
 }

 using Z::A;

 template <typename U> struct B
 {
 #ifdef FAILS
  typedef A<U> A;  
  // Fails to compile with gcc 4.3.0 20070323
  //generic_test.cpp:13: error: declaration of 'typedef struct Z::A<U> B<U>::A'
  //generic_test.cpp:4: error: changes meaning of 'A' from 'struct Z::A<U>'
  // Does not fail with gcc 4.1.2
 #else
  typedef Z::A<U> A;
 #endif
 };

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The solution to the problem is to use the qualified name Z::A<U> in the typedef.

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CategoryCpp CategoryCppTemplates