cpp20

There is constexpr, consteval but constinit is not described.
It could be worth to add it.

First of all, great library!

I am having some confusion in understanding the role of values_first2 in set_difference_by_key as mentioned here.

In general terms, the result of set difference D = A - B will not contain values from B therefore values_first2 can never be part of D. So `val

There is some inconsistency in the documentation for cub::DeviceSpmv (https://nvlabs.github.io/cub/structcub_1_1_device_spmv.html). The overview says

The SpMV computation performs the matrix-vector operation y = alpha*A*x + beta*y,

But the function signature of CsrMV has neither alpha nor beta, and the function's description says

This function performs the matrix-vector 

The documentation says this "Even though mp-units library does not implement any Linear Algebra types it is generic enough to be used with other Linear Algebra libraries existing on the market.". A set of examples using Eigen would be helpful. Blaze would probably be good too, but personally I don't use it so it's a lower priority for me.

Hey, is there any method to outputting the fps that I get in say lava-lamp.exe into a text file? preferably through the command line / no user input needed.

The problem is that the OpenCL types in https://github.com/triSYCL/triSYCL/blob/master/include/triSYCL/opencl_types.hpp are defined on the host according to the x86-64 Linux ABI which depends on the CPU & OS instead of using the description from https://www.khronos.org/registry/OpenCL/specs/2.2/html/OpenCL_C.html#built-in-scalar-data-types

Note that the system-wide cl_size_t has been removed