signed chars are not converted to str: is this intentional?

[YangJiao1996]

I've been using signed char instead of undecorated char in my code, and in the generated bindings they seem to be converted to Python ints instead of strs.

Sample code would be something like this in C++:

m.def("pass_signed_char", [](signed char c) { return c; });

And in Python:

example.pass_char("h") # Will get 105 instead of "h"

I read through the documentation and the tests in test_builtin_casters.cpp and test_builtin_casters.py and neither of them are testing signed chars and whether the char character types will be converted to str instead of int.

I wonder if this is by design or just an oversight?

[Skylion007]

We never designed any of the casters with the intent of using signed chars. You can always do a conversion of the return value to unsigned chars with a lambda or function wrapper. The fact that unsigned chars gets cast to anything at all is surprising, it seems they are implicitly convertible to int which is why they work at all: https://en.cppreference.com/w/cpp/language/implicit_conversion

[YangJiao1996]

This makes sense, as the documentation never mentions signed char or unsigned char.