struct_not_packed.hpp

// This is for not packed structs but _NOT_ for cl_typeN structs
#define BOOST_COMPUTE_ADAPT_STRUCT_NOT_PACKED(type, name, members) \
    BOOST_COMPUTE_TYPE_NAME(type, name) \
    namespace boost { namespace compute { \
    template<> \
    inline std::string type_definition<type>() \
    { \
        std::stringstream declaration; \
        declaration << "typedef struct {\n" \
                    BOOST_PP_SEQ_FOR_EACH( \
                        BOOST_COMPUTE_DETAIL_ADAPT_STRUCT_INSERT_MEMBER, \
                        type, \
                        BOOST_COMPUTE_PP_TUPLE_TO_SEQ(members) \
                    ) \
                    << "} " << type_name<type>() << ";\n"; \
        return declaration.str(); \
    } \
    namespace detail { \
    template<> \
    struct inject_type_impl<type> \
    { \
        void operator()(meta_kernel &kernel) \
        { \
            kernel.add_type_declaration<type>(type_definition<type>()); \
        } \
    }; \
    inline meta_kernel& operator<<(meta_kernel &k, type s) \
    { \
        return k << "(" << #name << "){" \
               BOOST_PP_SEQ_FOR_EACH_I( \
                   BOOST_COMPUTE_DETAIL_ADAPT_STRUCT_STREAM_MEMBER, \
                   s, \
                   BOOST_COMPUTE_PP_TUPLE_TO_SEQ(members) \
               ) \
               << "}"; \
    } \
    }}}

// Internal (This is for cl_typeN structs)
#define BOOST_COMPUTE_ADAPT_CL_VECTOR_STRUCT_NAME(type, n, name) \
    BOOST_COMPUTE_TYPE_NAME(type, name) \
    namespace boost { namespace compute { \
    namespace detail { \
    inline meta_kernel& operator<<(meta_kernel &k, type x) \
    { \
        k << "(" << type_name<type>() << ")"; \
        k << "("; \
        for(size_t i = 0; i < n; i++){ \
            k << k.lit(x.s[i]); \
            \
            if(i != n - 1){ \
                k << ","; \
            } \
        } \
        k << ")"; \
        return k; \
    } \
    }}}

// This is for cl_typeN structs   
#define BOOST_COMPUTE_ADAPT_CL_VECTOR_STRUCT(type, n) \
    BOOST_COMPUTE_ADAPT_CL_VECTOR_STRUCT_NAME(BOOST_PP_CAT(cl_, BOOST_PP_CAT(type, n)), n, BOOST_PP_CAT(type, n))
    
BOOST_COMPUTE_ADAPT_CL_VECTOR_STRUCT(float, 2) // cl_float2
BOOST_COMPUTE_ADAPT_CL_VECTOR_STRUCT(uchar, 4) // cl_uchar4
BOOST_COMPUTE_ADAPT_STRUCT_NOT_PACKED(custom_type, custom_type, (someInt, somePoint))

// You have to rembember that in OpenCL cl_float2 is float2, so
// Boost Compute function that transforms float2 should look like that:

BOOST_COMPUTE_FUNCTION(cl_float2, func_cl_float2, (cl_float2 b),
{
    float2 a = b; // not cl_float2 a = b;, as there is no cl_float2 defined in OpenCL
    a.x = 5;
    return a;
});