gistfile1.txt

#include <metal_stdlib>
using namespace metal;

// only intended for 32-bit int types
template<typename T>
static T bitfieldExtract(T val, int offset, int size)
{
    val <<= 32 - (offset + size);
    val >>= 32 - size;
    return val;
}

kernel void kern(uint invocation [[ thread_index_in_threadgroup ]])
{
    int2 x = bitfieldExtract(int2(0x01234567, 0x89abcdef), int(invocation)*4, 4);
}

// generates:
// test.metal:15:14: error: no matching function for call to 'bitfieldExtract'
//     int2 x = bitfieldExtract(int2(0x01234567, 0x89abcdef), int(invocation)*4, 4);
//              ^~~~~~~~~~~~~~~
// test.metal:6:10: note: candidate template ignored: couldn't infer template argument 'T'
// static T bitfieldExtract(T val, int offset, int size)
//          ^
// 1 error generated.