You can do that in any language by constructing something (ie. struct in c#) in that language that consists of multiple instances of primitive types that store the bits. For example if you want to create a 128-bit data type you'd create a struct holding two 64-bit integers on x64 or 4 32-bit integers on x86 machine. You can see how it is done in C for a 256-bit integer with 4x 64-bit chunks and 8x 32-bit chunks.