compiling with _GLIBCXX_DEBUG gives errors

[notestaff]

Does this problem persist on the current master?

• I have verified the issue on the current master

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

Compiling a seqan3-dependent program with -D_GLIBCXX_DEBUG (debug mode) gives errors that don't happen without debug mode:

In file included from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/marti2/include/marti2/marti2_utils.hpp:17,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/marti2/marti2_utils.cpp:9:
/data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/alphabet/nucleotide/dna4.hpp: In function 'constexpr seqan3::dna4_vector seqan3::literals::operator""_dna4(const char*, std::size_t)':
/data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/alphabet/nucleotide/dna4.hpp:260:17: error: variable 'r' of non-literal type 'seqan3::dna4_vector' {aka 'std::__debug::vector<seqan3::dna4>'} in 'constexpr' function only available with '-std=c++2b' or '-std=gnu++2b'
  260 |     dna4_vector r;
      |                 ^
In file included from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/x86_64-conda-linux-gnu/include/c++/12.3.0/vector:74,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/x86_64-conda-linux-gnu/include/c++/12.3.0/functional:62,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/submodules/cereal/include/cereal/cereal.hpp:35,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/submodules/cereal/include/cereal/archives/binary.hpp:32,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/core/concept/cereal.hpp:20,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/alphabet/concept.hpp:18,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/alphabet/views/char_strictly_to.hpp:17,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/marti2/marti2_utils.cpp:2:
/data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/x86_64-conda-linux-gnu/include/c++/12.3.0/debug/vector:117:11: note: 'std::__debug::vector<seqan3::dna4>' is not literal because:
  117 |     class vector
      |           ^~~~~~
/data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/x86_64-conda-linux-gnu/include/c++/12.3.0/debug/vector:117:11: note:   'std::__debug::vector<seqan3::dna4>' does not have 'constexpr' destructor
In file included from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/alphabet/aminoacid/all.hpp:70,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/alphabet/all.hpp:185,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/marti2/include/marti2/marti2_defs.hpp:11,
                 from /data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/marti2/include/marti2/marti2_utils.hpp:20:
/data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/alphabet/aminoacid/aa10li.hpp: In function 'constexpr seqan3::aa10li_vector seqan3::literals::operator""_aa10li(const char*, size_t)':
/data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/include/seqan3/alphabet/aminoacid/aa10li.hpp:233:19: error: variable 'r' of non-literal type 'seqan3::aa10li_vector' {aka 'std::__debug::vector<seqan3::aa10li>'} in 'constexpr' function only available with '-std=c++2b' or '-std=gnu++2b'
  233 |     aa10li_vector r;
      |                   ^
/data/ilya/iwork/marti/tmp/wtree/is-231002-1155-marti-cpp/build/marti2_envs/x86_64-conda-linux-gnu/include/c++/12.3.0/debug/vector:117:11: note: 'std::__debug::vector<seqan3::aa10li>' is not literal because:
  117 |     class vector
      |           ^~~~~~

Expected Behavior

We'd like to compile a seqan3-dependent program under C++20 standard in debug mode, without errors.

Steps To Reproduce

Add -D_GLIBCXX_DEBUG when compiling.

Environment

`
uname -a
Linux bpb23-acc 5.4.0-136-generic #153-Ubuntu SMP Thu Nov 24 15:56:58 UTC 2022 x86_64 GNU/Linux

$CXX --version
x86_64-conda-linux-gnu-c++ (conda-forge gcc 12.3.0-2) 12.3.0
Copyright (C) 2022 Free Software Foundation, Inc.
conda env export | grep seqan3
  - seqan3=3.3.0=hdfd78af_0
`

Anything else?

As always, thanks for your work on seqan!

@eseiler

[eseiler]

Hey there,

I'll look at this on Wednesday (still on holiday today and tomorrow).

It should only use constexpr vectors if the compiler supports it and our nightlies with glibcxx_debug also work, but they might just not cover your use case.

Do you have a minimal example that fails to compile? I. E., how do you use the alphabet vector?

[SGSSGene]

I can confirm this bug on godbolt with the newest seqan version (it works with seqan 3.2.0):
https://godbolt.org/z/fzfTqfdbq

[SGSSGene]

I believe this is a bug in gcc/libstdc++
We can reproduce it here (without seqan): https://godbolt.org/z/oTfhEWrvd

I found this entry on bugzilla, showing at least one person is aware of this issue: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104748

To solve this, we don't guarentee that ""_dna is constexpr, we could put in another switch, removing the constexpr if -D_GLIBCXX_DEBUG is set, what do you think @eseiler ?

[SGSSGene]

I suggested following fix: #3222