gbc does not handle UTF-8 characters in attribute values when generating C++ (and C#)

[codeandroid]

gbc successfully parses UTF-8 encoded bond files with attribute values like this one:

namespace demo

struct Thing
{
     [DisplayName("∑")]
     0: int32 sum;
}

It generates the UTF-8 encoded JSON schema file without issues:

(...)
{
    "attrName": [
        "DisplayName"
    ],
    "attrValue": "∑"
}

Unfortunately, gbc fails when generating C++ (or C#) code with an error:

gbc.exe: ...\demo_types.cpp: commitAndReleaseBuffer: invalid argument (invalid character)

I tried Haskell string escaping but to no avail.

I also found #687 but that issue relates to C++ identifiers.

I see no immediate reason (and could not find one by searching through the repo) why UTF-8 encoded attribute values could not be properly generated in C++ code. GCC and Clang should pose no problem. For MSVC this might require setting the byte-order-mark in the generated source file though I'm not 100% sure about that (see Docs ).