convert methods should return a std::string rather than const char * about oboe

[philburk]

Who deletes the std::string?

[philburk]

const char * may be old school but it has advantages.
The caller does not have to delete the string.
So it can easily be used in logs.
Also std::string may cause a memory allocation, which should be avoided in real-time audio.

[mnaganov]

There is no need to delete the string. I think, Don is proposing to return 'std::string' by value, not as a pointer to an allocated object. And in those cases compilers usually provide optimizations to avoid unneeded allocations or copying.

The advantage of returning an std::string is that the error text may be composed on the fly.

As for the 'real-time' issue—if an error happens it's already a problem, and requires taking the error handling code path, which is allowed to be non-optimal (think of exception handling).

[philburk]

It seems like we are taking something very simple and converting it to something more complex.
If we want to add the result code to the string, we could could add a convenience function that called the simple (const char *) function then added the result code and returned a std::string.
Or the app could do that very easily.

[dturner]

The motivation isn't primarily because we want to return a result code (although it does help with that), it's that users of the Oboe library may prefer to receive a std::string over a C-style string.

Some benefits of std::string over C strings: https://embeddedartistry.com/blog/2017/7/24/stdstring-vs-c-strings

As for your point about memory allocation - this is true and we should be very clear in the comments and documentation that the convertToText method shouldn't be called in the data callback under normal conditions.

I've asked some partners for their opinions on what they'd prefer - maybe C-style strings are still en vogue for audio programmers.

[dturner]

Things are better in C++17 but Android Studio only supports up to C++14 so closing for now.