std::optional::value unavailable on earlier macOS versions about peaclock

[octobanana]

@Dluzhnevsky It sounds like the compiler being used doesn't fully support the C++17 standard. What compiler and version are you using?

According to cppreference, std::optional has support since gcc 7 and clang 4.

[Dluzhnevsky]

@octobanana Yeah, it is the C++17 support problem. I've heard a lot of people complaining about it.

I am using clang: Apple LLVM version 10.0.0 (clang-1000.11.45.5). And it is still lacking the C++17 support.

[octobanana]

Have you looked into installing an up to date compiler, such as gcc, through a package manager like brew?

[octobanana]

Unfortunately, supporting compilers that do not implement the C++17 standard is not a goal of this project.

Either updating to macOS 10.14 or installing a more recent compiler, such as llvm or gcc, should fix the issue.

As installing a compiler is not within the scope of this project, this issue is being closed. Please feel free to reopen or create a new issue if you have any other questions.