I'm compiling some code on the Cell processor main CPU using its dedicated gcc. The code is calling mpl::apply1 onto a custom meta-function. The compiler -v is : ppu-g++ -v Using built-in specs. Target: ppu Configured with: ../toolchain/gcc/configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-as=/usr/bin/ppu-as --with-ld=/usr/bin/ppu-ld --enable-threads --with-system-zlib --disable-checking --enable-__cxa_atexit --disable-libunwind-exceptions --enable-languages=c,c++,fortran,ada --disable-nls --enable-clocale=gnu --enable-version-specific-runtime-libs --with-long-double-128 --program-prefix=ppu- --disable-bootstrap --host=ppu --build=powerpc64-unknown-linux-gnu --target=ppu Thread model: posix gcc version 4.1.1 The code : template<class T> struct scalar_mode { typedef mpl::false_ status; struct base { template<class Type> struct apply : mpl::if_< is_same<T,none>, Type, T> {}; }; }; typedef mpl::apply1< scalar_mode<none>::base, float>::type type; The compiler errors are : ../../../lib/include/boost-1_35/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp: In instantiation of 'const int boost::mpl::aux::template_arity_impl<nt2::scalar_mode<nt2::none>::base, 1>::value': ../../../lib/include/boost-1_35/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp:93: instantiated from 'const int boost::mpl::aux::template_arity<nt2::scalar_mode<nt2::none>::base>::value' ../../../lib/include/boost-1_35/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp:98: instantiated from 'boost::mpl::aux::template_arity<nt2::scalar_mode<nt2::none>::base>' ../../../lib/include/boost-1_35/boost/mpl/aux_/preprocessed/gcc/apply.hpp:48: instantiated from 'boost::mpl::apply1<nt2::scalar_mode<nt2::none>::base, float>' essais/simd.cpp:13: instantiated from here ../../../lib/include/boost-1_35/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp:85: error: call of overloaded 'arity_helper(boost::mpl::aux::type_wrapper<nt2::scalar_mode<nt2::none>::base>, boost::mpl::aux::arity_tag<1>)' is ambiguous ../../../lib/include/boost-1_35/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp:30: note: candidates are: char (& boost::mpl::aux::arity_helper(...))[1] ../../../lib/include/boost-1_35/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp:37: note: char (& boost::mpl::aux::arity_helper(boost::mpl::aux::type_wrapper<F<T1> >, boost::mpl::aux::arity_tag<1>))[2] [with F = nt2::scalar_mode<T>::base, T1 = nt2::none] ../../../lib/include/boost-1_35/boost/mpl/aux_/preprocessed/gcc/template_arity.hpp:37: note: char (& boost::mpl::aux::arity_helper(boost::mpl::aux::type_wrapper<F<T1> >, boost::mpl::aux::arity_tag<1>))[2] [with F = nt2::scalar_mode<T>::base, T1 = nt2::none] I know that "officially" boost is not supported on this kidn of platform but most of my code compiles and works flawlessly except for this. Any hints on what to do to fix this even locally ? Thanks in advance