Cast the constant to the right type - FIX #2156

[airween]

A possible solution for #2156.

[zimmerle]

Hi @airween, hide the warning is definitely not the solution for the problem.

[airween]

Hi @zimmerle,

could you explain why is this just hiding of warning?

I made a small test file to demonstrate my idea:
https://gist.github.com/airween/c2f3ff400e4c4a94dcbed9aec6eca48a

Here is my opinion:

• the std::string is a sequence with element type char, therefore each item value could be between -127 and 128
• consider somehow there is an item with value 160 - see the example line 25.
• when the casting comes (line 26-27), then the values converted from unsigned char to signed char, so the 160 will -96
• it's same what the static_cast<> does

In the example you can see that's not just the warning hide, it really removes the NBSP from sequence.

May be I'm wrong, but I'm very curious your opinion.