id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
11673	locale: Invalid static_cast	Ben Wiederhake <Ben.Wiederhake@…>	Artyom Beilis	"When trying to compile certain versions of boost (see below which versions), I see the following compilation error when using gcc-5.2:

`libs/locale/src/shared/message.cpp:438:64: error: invalid static_cast from type 'const wchar_t*' to type 'const char*'`

This is the relevant code:

{{{
template<typename CharType>
...
CharType const *p = ...;
CharType const *e = ...;
...
state = pj_winberger_hash::update_state(state,
    static_cast<char const *>(p),
    static_cast<char const *>(e));
}}}

In essence, the code tries to *re-interpret* the argument as a sequence of chars and feeds it into the `update_state` function of some kind of hash. I don't understand all the details, but I'm pretty sure this is not a `static_cast` anymore and the compilation error is valid.

I can see the following options to resolve the issue:
- Declare any template instantiations with non-char `CharType` as illegal. I view this as a very bad if not insane idea.
- Change it from `static_cast` to `reinterpret_cast` because that's precisely what is needed here. I view this as a good idea.

This issue is visible in branch master of boostorg/boost.
This issue seems to have been visible since the commit 8f94dbbf3563381ebf1f8db96e16692f8e351db9 (""Inline namespace test version."") in boostorg/type_traits, introduced by commit 9eae98d8714f8cb4114e799bbb4e10f45919dda4 (""Update type_traits from master"") in boostorg/boost.
"	Bugs	closed	Boost 1.60.0	locale	Boost 1.59.0	Problem	fixed