Using std::string_view and std::span

[sagaceilo]

It would be nice, if library would use string_view and span more extensively. It would remove not needed copying expensive strings all over the place.

returning string_view here for example.

rapidcsv/src/rapidcsv.h

Line 1393 in 03133b5

std::string GetColumnName(const size_t pColumnIdx) const

Or
std::vector<T> GetRow(const std::string& pRowName)
To be
std::span<const T> GetRow(const std::string_view pRowName)
Thi way it literaly zero allocation. Both when cnverting literal like GetRow("blah blah blah") and accessing result.

[sagaceilo]

Also functions like ToStr would benefit from if constexpr () to compile out code.
And using std::is_same_v<T,int> seems more appropriate here than using typeid(). As is_same_v is compile time const, and typeid uses rtti.

[d99kris]

I have converted this issue into a feature request.

Rapidcsv currently supports C++11, but given it's already 2026 it may be time to consider requiring C++14 or possibly C++17 (which adds std::string_view). But it's probably still early to require C++20 (which adds std::span). I am not inclined to support multiple minimum C++ versions via pre-compiler directives (#ifdef).

I will do some surveying on other C++ libraries minimum supported C++ versions. Any feedback from users of this library is also welcome here in this thread.

[sagaceilo]

Sure. std::span could be replaced with some rapidcsv::span<> as implementation would be as short as dozen of lines of code. And adding begin() end() would cover most cases where You would like to use range for loops.
I agree that relying on C++20 is not a good idea, as most codebase I work with are still C+17 and 20 is not that widely adopted still in many places.
I also have my own ArraySpan<> everywhere anyway.

[aviiciii]

looking forward to this