Names clash between variant-lite and expected-lite

[flexferrum]

I included both nonstd/expected.hpp and nonstd/variant.hpp in one file and got the following error:

/projects/flexferrum-Jinja2Cpp/thirdparty/nonstd/expected-light/include/nonstd/expected.hpp:531:8: error: redefinition of ‘struct nonstd::in_place_t’
 struct in_place_t{};
        ^
/projects/flexferrum-Jinja2Cpp/thirdparty/nonstd/variant-light/include/nonstd/variant.hpp:272:8: error: previous definition of ‘struct nonstd::in_place_t’
 struct in_place_t {};
        ^

[flexferrum]

UPD: If include 'expected.hpp' before 'variant.hpp' and set 'nonstd_lite_HAVE_IN_PLACE_TYPES' macro manually, errors will become more serous:

In file included from /projects/flexferrum-Jinja2Cpp/src/internal_value.h:9:0,
                 from /projects/flexferrum-Jinja2Cpp/src/expression_evaluator.h:4,
                 from /projects/flexferrum-Jinja2Cpp/src/filters.h:4,
                 from /projects/flexferrum-Jinja2Cpp/src/filters.cpp:1:
/projects/flexferrum-Jinja2Cpp/thirdparty/nonstd/variant-light/include/nonstd/variant.hpp:1035:53: error: expected ‘)’ before ‘,’ token
     explicit variant( nonstd_lite_in_place_type_t(T), Args&&... args)
                                                     ^
/projects/flexferrum-Jinja2Cpp/thirdparty/nonstd/variant-light/include/nonstd/variant.hpp:1043:53: error: expected ‘)’ before ‘,’ token
     explicit variant( nonstd_lite_in_place_type_t(T), std::initializer_list<U> il, Args&&... args )
                                                     ^
/projects/flexferrum-Jinja2Cpp/thirdparty/nonstd/variant-light/include/nonstd/variant.hpp:1051:52: error: ‘I’ is not a type
     explicit variant( nonstd_lite_in_place_index_t(I), Args&&... args )
                                                    ^
/projects/flexferrum-Jinja2Cpp/thirdparty/nonstd/variant-light/include/nonstd/variant.hpp:1051:54: error: expected ‘)’ before ‘,’ token
     explicit variant( nonstd_lite_in_place_index_t(I), Args&&... args )
                                                      ^
/projects/flexferrum-Jinja2Cpp/thirdparty/nonstd/variant-light/include/nonstd/variant.hpp:1059:52: error: ‘I’ is not a type
     explicit variant( nonstd_lite_in_place_index_t(I), std::initializer_list<U> il, Args&&... args )

[flexferrum]

I'm considering the following way of fix: move common types, macros etc. to separate repo and then combine the 'production' headers via Jinja2 - just include one Jinja2 template into another. It allows to keep the common code consistent.

[martinmoene]

This is a 'duplicate' of issue 14 at expected-lite .

I'd like to keep the shared "in_place infrastructure" as simple as it is now and refrain from file generation for any-lite, optional-lite and expected-lite.

I've had a go at using optional-lite's (etc.) in_place setup before, but was not immediately successful (can't remember why). Also I can't remember from the top of my head why expected-lite's in_place is as it is. Further, I have a longstanding action to update expected-lite (old repo) (new repo) to the latest proposal, a moving target.

References:

• in_place at cppreference
• nonstd-lite issue 17: Align in_place between any, expected, optional, variant
• variant-lite issue #1: [isocpp-lib] CH 3, p0032r2 -- let's not have too clever tags
• expected-lite issue 14: can't work with optional-lite because of nonstd::in_place_t
• expected-lite, issue 3: Update expected-lite to proposal p0323r7 (was 6/5)
• expected-lite, issue 20 (old repo): Update expected-lite to proposal p0323r6 (was 5)
• P0323rx std::expected: Update to latest proposal

[martinmoene]

Done per nonstd-lite issue 17.

[flexferrum]

I'll try to check it out tonight. Thanks!

[flexferrum]

It works!

[martinmoene]

Nice! Thanks for letting me know.