I got a report that Clang fails to compile the filesystem lib, with
the following error:
/home/jwakely/gcc/latest/include/c++/6.0.0/experimental/bits/fs_path.h:563:18: fatal
error: explicit specialization of
'std::experimental::filesystem::v1::path::__is_encoded_char<char>' after
instantiation
struct path::__is_encoded_char<char> : std::true_type
^~~~~~~~~~~~~~~~~~~~~~~
/home/jwakely/gcc/latest/include/c++/6.0.0/experimental/bits/fs_path.h:104:9:
note: implicit instantiation first required here
: decltype(__is_path_src(std::declval<_Source>(), 0))
^
The problem is that the path::_Cmpt constructors do overload
resolution on the path constructors, which requires the explicit
specializations of __is_encoded_char. Solved by moving the definition
of _Cmpt after the specializations.
I'm still reducing it to report a g++ bug for the missed diagnostic.
Tested powerpc64le-linux, committed to trunk. This is unfortunately
too late for 5.3, so I'll fix it on the branch when it reopens.
commit 0bd97117b71c759cbccfe9d19ea09b96c3bce472
Author: Jonathan Wakely <[email protected]>
Date: Tue Dec 1 10:30:31 2015 +0000
Define path::_Cmpt after specializing path::__is_encoded_char
* include/experimental/bits/fs_path.h (path::_Cmpt): Move definition
after path::__is_encoded_char explicit specializations.
diff --git a/libstdc++-v3/include/experimental/bits/fs_path.h b/libstdc++-v3/include/experimental/bits/fs_path.h
index 40462a6..98820ad 100644
--- a/libstdc++-v3/include/experimental/bits/fs_path.h
+++ b/libstdc++-v3/include/experimental/bits/fs_path.h
@@ -549,16 +549,6 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
std::string _M_what = _M_gen_what();
};
- struct path::_Cmpt : path
- {
- _Cmpt(string_type __s, _Type __t, size_t __pos)
- : path(std::move(__s), __t), _M_pos(__pos) { }
-
- _Cmpt() : _M_pos(-1) { }
-
- size_t _M_pos;
- };
-
template<>
struct path::__is_encoded_char<char> : std::true_type
{ using value_type = char; };
@@ -575,6 +565,16 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
struct path::__is_encoded_char<char32_t> : std::true_type
{ using value_type = char32_t; };
+ struct path::_Cmpt : path
+ {
+ _Cmpt(string_type __s, _Type __t, size_t __pos)
+ : path(std::move(__s), __t), _M_pos(__pos) { }
+
+ _Cmpt() : _M_pos(-1) { }
+
+ size_t _M_pos;
+ };
+
// specialize _Cvt for degenerate 'noconv' case
template<>
struct path::_Cvt<path::value_type>
