[Bug c++/42533] New: boost_concept_check.h - _SGIAssignableConcept broken the class self contains

[Bug c++/42533] New: boost_concept_check.h - _SGIAssignableConcept broken the class self contains

[baiyang at gmail dot com]

for example, I have a class like this:

class MyClass
{
public: 
    MyClass() ...
    MyClass(IN const MyClass& rhs) ...
    MyClass& operator=(IN const MyClass& rhs)...

private:
    typedef std::map< string, MyClass > KEYTBL; // Self contains
    struct PROP {
       ...
       KEYTBL tblKeys;
       ...
    };

    typedef SMART_POINTER< PROP > HPROP;
    HPROP m_hProp;
};

As the example shown, If with out (early and msvc) the boost concept check,
then everything is perfect ok, Because C++ will try to instantiation the map
only when we need to use it. BUT the boost conept check (_SGIAssignableConcept)
just broken the c++ delay instantiation rule, so everything is broken here.


-- 
           Summary: boost_concept_check.h - _SGIAssignableConcept broken the
                    class self contains
           Product: gcc
           Version: 4.3.2
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: baiyang at gmail dot com
  GCC host triplet: OpenSolaris 2009.06 x86
GCC target triplet: OpenSolaris 2009.06 x86


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42533

[Bug c++/42533] boost_concept_check.h - _SGIAssignableConcept broken the class self contains

[baiyang at gmail dot com]

------- Comment #1 from baiyang at gmail dot com  2009-12-29 10:43 -------
PS: the above example is a typical usage of the self contain skill. In this
exapmle, the coder will ensure every really usage point (i.e. every possible
template instantiation point) of 'm_hProp->tblKeys' in the code are all at
outside of MyClass' defination scope. So we guarantee the class has been fully
defined before using it. 

BUT the "concept check" just cancelled the delay instantiation mechanism, so
the code doesn't work anymore.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42533

[Bug libstdc++/42533] boost_concept_check.h - _SGIAssignableConcept broken the class self contains

[paolo dot carlini at oracle dot com]

------- Comment #2 from paolo dot carlini at oracle dot com  2009-12-29 10:56 -------
After so many years since that idea, we are not interested in squeezing more
from that interesting (but outdated) idea of simulating concept checks in the
library. Long term, we want proper concept checks in the language. Thus, please
just build your translation unit without defining _GLIBCXX_CONCEPT_CHECKS (or
do not build the entire library with --enable-concept-checks and enable the
checks only on a case by case basis)


-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|major                       |normal
             Status|UNCONFIRMED                 |RESOLVED
          Component|c++                         |libstdc++
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42533