struct TypeWrap{T} end
TypeWrap(T) = TypeWrap{T}()
Base.:*(x::Number, ::TypeWrap{T}) where T = T(x)

Allow type conversion via multiplication, like 5i32 for 5 * i32 where i32 is a TypeWrap.

Examples

import AcceleratedKernels as AK
u32 = AK.TypeWrap{UInt32}
println(typeof(5u32))

# output
UInt32

This is used e.g. to set integer literals inside kernels as u16 to ensure no indices are promoted beyond the index base type.

For example, Metal uses UInt32 indices, but if it is mixed with a Julia integer literal (Int64 by default) like in src[ithread + 1], we incur a type cast to Int64. Instead, we can use src[ithread + 1u16] or src[ithread + 0x1] to ensure the index is UInt32 and avoid the cast; as the integer literal 1u16 has a shorter type than ithread, it is automatically promoted (at compile time) to the ithread type, whether ithread is signed or unsigned as per the backend.

# Defaults defined
1u8, 2u16, 3u32, 4u64
5i8, 6i16, 7i32, 8i64