Pipe notation does not compile with ranges::to

[joergi-w]

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

Compiler error with the pipe notation of seqan3::ranges::to

g++-12 -I ../repo/seqan3/include -I ../repo/seqan3/submodules/sdsl-lite/include -I ../repo/seqan3/submodules/cereal/include -std=c++20 -o args args.cpp

args.cpp: In function 'int main()':
args.cpp:10:75: error: no match for 'operator|' (operand types are 'std::ranges::transform_view<std::ranges::ref_view<std::vector<seqan3::dna5> >, <lambda(auto:23&&)> >' and '<unresolved overloaded function type>')
   10 |     seqan3::dna4_vector conv = seq | seqan3::views::convert<seqan3::dna4> | seqan3::ranges::to<std::vector>;
      |                                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      |                                    |                                                        |
      |                                    |                                                        <unresolved overloaded function type>
      |                                    std::ranges::transform_view<std::ranges::ref_view<std::vector<seqan3::dna5> >, <lambda(auto:23&&)> >

Expected Behavior

The following code snippets should be equivalent, but the first version works, the second not:

1 (everything fine)

seqan3::dna4_vector conv = seqan3::ranges::to<std::vector>(seq | seqan3::views::convert<seqan3::dna4>);

2 (compilation fails)

seqan3::dna4_vector conv = seq | seqan3::views::convert<seqan3::dna4> | seqan3::ranges::to<std::vector>;

Steps To Reproduce

Minimum example:

#include <seqan3/alphabet/nucleotide/dna4.hpp>
#include <seqan3/alphabet/nucleotide/dna5.hpp>
#include <seqan3/utility/range/to.hpp>
#include <seqan3/utility/views/convert.hpp>

int main()
{
    using namespace seqan3::literals;
    seqan3::dna5_vector seq = "CAGUCAGUCAGUCAGU"_dna5;
    seqan3::dna4_vector conv = seq | seqan3::views::convert<seqan3::dna4> | seqan3::ranges::to<std::vector>;
    return 0;
}

Environment

- Operating system: MacOS 11.6.5
- SeqAn version: commit e51658df (current master)
- Compiler: gcc 11.3.0 and 12.1.0 (Homebrew)

Anything else?

No response

[eseiler]

Needs to be seqan3::ranges::to<std::vector>(). It's a function object in C++23.

[joergi-w]

Oh, thanks! That's an easy fix ;)
I was adjusting some code from seqan3::views::to to the new API and failed at this point.
I think this issue can be closed.