const in CBLAS_LAYOUT et al. in CBLAS

[jgpallero]

Inspecting the cblas.h file I can see that the qualifier const is employed in all input arguments (even with those called by value) with the exception of the enumerated types CBLAS_LAYOUT et al. Two questions:

1. Why const is not used with the enumerated types?
2. Function cblas_sgemv maintains const with the enumerated types. I suppose it is a forget from previous versions (I seem to remember that const was used in previous versions). Am I right?

[weslleyspereira]

Why const is not used with the enumerated types?

I don't think there is a good reason for that. Maybe for improving readability by reducing verbosity. I am not aware of any performance gain for using const in passing variables by value. By not using const you allow for the variable to be modified inside the routine, but I don't think this was the original reason.