windows msvc2019

[yangxingpping]

Expected Behavior

Actual Behavior

example.cpp https://raw.githubusercontent.com/boost-experimental/te/master/include/boost/te.hpp(18): warning C4068: unknown pragma 'GCC' https://raw.githubusercontent.com/boost-experimental/te/master/include/boost/te.hpp(298): error C2062: type 'bool' unexpected https://raw.githubusercontent.com/boost-experimental/te/master/include/boost/te.hpp(298): error C2143: syntax error: missing ';' before '{' https://raw.githubusercontent.com/boost-experimental/te/master/include/boost/te.hpp(298): error C2447: '{': missing function header (old-style formal list?) https://raw.githubusercontent.com/boost-experimental/te/master/include/boost/te.hpp(304): error C2062: type 'bool' unexpected https://raw.githubusercontent.com/boost-experimental/te/master/include/boost/te.hpp(304): error C2143: syntax error: missing ';' before '{' https://raw.githubusercontent.com/boost-experimental/te/master/include/boost/te.hpp(304): error C2447: '{': missing function header (old-style formal list?)

(18): error C3203: 'Drawable': unspecialized class template can't be used as a template argument for template parameter 'I', expected a real type (18): error C2039: 'draw': is not a member of 'boost::ext::te::v1::poly' (18): note: see declaration of 'boost::ext::te::v1::poly' (21): error C2641: cannot deduce template arguments for 'Circle' (22): error C2641: cannot deduce template arguments for 'Square' ## Steps to Reproduce the Problem

1.https://godbolt.org/ 1. 1.

Specifications

• Version: x64 msvc 19.latest
• Platform: windows
• Subsystem: /std:c++20