This makes it possible to call public functions that take a string class
as a template parameter and return an object of that class (implemented
through the StringByteSink helper class) also with the CharString class,
even though this class doesn't actually provide the public API required
by StringByteSink.
This makes it possible to use such more modern APIs also internally.
Some of this code was originally written as C code and some of this code
was originally written as C++ code but made to resemble the then already
existing code that had once been C code. Changing it all to normal C++
now will make it easier and safer to work with going forward.
· Use unnamed namespace instead of static.
· Use reference instead of non-nullable pointer.
· Use bool instead of UBool.
· Use constexpr for static data.
· Use U_EXPORT instead of U_CAPI or U_CFUNC.
· Use the default calling convention instead of U_EXPORT2.
This is the normal standard way in C, C++ as well as Java and there's no
longer any reason for ICU to be different. The various internal macros
providing custom boolean constants can all be deleted and code as well
as documentation can be updated to use lowercase true/false everywhere.
- Use STATIC_NEW for mutex creation, to avoid order-of-destruction problems
by avoiding destruction altogether, while avoiding memory leak reports.
- Remove UConditionVar, replace with direct use of std::condition_variable
Remove the dependencies from the ICU library code on static constructors
that were introduced by using std::mutex and condition variables. The
mutexes are lazily initialized by embedding them as local static variables
in getter functions, and relying on the C++ compiler/runtime to do thread
safe initialization of them.
