[Boost-users] [type_erasure] [docs]contrast with boost::any

On 07/18/12 00:13, Lorenzo Caminiti wrote:

Hello all,

*** The review of Steven Watanabe's proposed Boost.TypeErasure library begins on July 18, 2012 and ends on July 27, 2012. ***

The page: http://steven_watanabe.users.sourceforge.net/type_erasure/libs/type_erasure/... says: x is approximately equivalent to a boost::any however, it doesn't say how te::any differs from boost::any. The attached shows that a boost::any can change it's type, and, as such, is somewhat like boost::variant. However, te::any, once it's created, cannot change it's type, AFAICT. At least that's what the attached code indicates when compiled with: #define SHOW_TE_FIXED_TYPE With that #define, the error produced by gcc4.8 is: ../../../boost/type_erasure/any.hpp:702:9: note: mismatched types 'const boost::type_erasure::assignable' and 'void' _boost_type_erasure_assign_impl( ^ In contrast, without that #define, the boost::any has no problem changing it's type and produces output: typeinfo(bnd_value_ptr_v)=double* typeinfo(bnd_displacement_v)=int a_any=stk_displacement_v; any_cast=0x97eb58 a_any=stk_value_ptr_v; any_cast=0; any_cast=0x97eb78 The code uses a compiler specific demangler, also attached. -regards, Larry