Inline temporary variable adds unnecessary cast

[DoctorKrolic]

Version Used:
Latest main

Steps to Reproduce:

var a = Math.Round(1.1D);
var b = a;

Inline variable a;

Expected Behavior:

var b = Math.Round(1.1D);

Actual Behavior:

var b = (double)Math.Round(1.1D);

[DoctorKrolic]

Futhermore, after executing code action, IDE doesn't suggest you remove unnecessary cast. So this is simplifier's problem: it cannot determine, that in the given context overload with double return type is used (I guess this is the core problem)

[CyrusNajmabadi]

Doubles are challenging due to the casts having semantics even when the types are exactly the same.

We likely want to be cautious about adding the explicit fp cast in the first place. Avoiding it if we can be sure it isn't necessary.

[DoctorKrolic]

Doubles are challenging due to the casts having semantics even when the types are exactly the same.

Wait what?! Can you give an example?

[CyrusNajmabadi]

Machines often execute fp operations on higher precision than 32 or 64 bits. Casting explicitly reduces the precision down to those levels. So you can get different results.

[pyoub]

i create a pr triying to fix this problem if you can review it please :)

[CyrusNajmabadi]

@pyoub if you ping me tomorrow I can take a look!

[pyoub]

@CyrusNajmabadi can you check the PR please @DoctorKrolic already did and didnt like approve the solution. so is there any suggestion?