1+++
2title = "`BOOST_OUTCOME_THREAD_LOCAL`"
3description = "How to mark variables as having thread local storage duration."
4+++
5
6Compiler-specific markup used to mark variables as having thread local storage duration.
7
8{{% notice note %}}
9This isn't used inside Outcome, but is used by its unit test suite.
10{{% /notice %}}
11
12*Overridable*: Define before inclusion.
13
14*Default*: To `thread_local` if the compiler implements C++ 11 `thread_local`, else `__thread` for the one supported compiler (older Mac OS XCode) which does not.
15
16*Header*: `<boost/outcome/config.hpp>`