libs/libxx/README.txt
^^^^^^^^^^^^^^^^^^^^^

This directory contains a fragmentary C++ library that will allow to build
only the simplest of C++ applications. In the deeply embedded world, that
is probably all that is necessary. If you have a need for more extensive
C++ support, the following libraries are recommended:

- libstdc++ (part of GCC)
- STLport http://www.stlport.org/
- uClibc++ http://cxx.uclibc.org/
- uSTL http://ustl.sourceforge.net/

There is a version of uClibc++ that has been customized for use with NuttX.
That version that can be found in the NuttX uClibc++ GIT repository. Refer
to the top-level uClibc++ README.txt file for installation instructions.

At present, only the following are supported here:

- void *operator new(std::size_t nbytes);
- void operator delete(void* ptr);
- void operator delete[](void *ptr);
- void __cxa_pure_virtual(void);
- int __aeabi_atexit(void* object, void (*destroyer)(void*), void *dso_handle);
- int __cxa_atexit(__cxa_exitfunc_t func, FAR void *arg, FAR void *dso_handle);

operator new
------------

This operator should take a type of size_t. But size_t has an unknown underlying
type. In the nuttx sys/types.h header file, size_t is typed as uint32_t
(which is determined by architecture-specific logic). But the C++
compiler may believe that size_t is of a different type resulting in
compilation errors in the operator. Using the underlying integer type
instead of size_t seems to resolve the compilation issues. Need to
REVISIT this.

Once some C++ compilers, this will cause an error:

Problem: "'operator new' takes size_t ('...') as first parameter"
Workaround: Add -fpermissive to the compilation flags