Standard placement operator

[Norman Feske]

Hello Daniel,

> [...] how do I use the std c++ new placement
> operator which take void *, i.e.
> 
> void * p = ::malloc(256);
> T * obj = new (p) T();
> 
> When I try to use this it cannot find the operator, only the Genode
> allocator version. I have 'cxx' in my target.mk

in the rare cases where the Genode base system needs a placement new
operator, we host it in the implementation file. For example,
'base/src/base/allocator/slab.cc' contains one. This way, the operator
is defined only if really intended, which avoids using it by accident.
It is a single line of code:

  inline void *operator new(size_t, void *at) { return at; }

Alternatively, if you are using the standard C++ library anyway, you may
use the definition provided by libsupc++. Just specify your LIBS
declaration in your 'target.mk' file as follows:

  LIBS = libc libm stdcxx

Now, you can just '#include <new>' and use the placement new operator
provided there.

Cheers
Norman

-- 
Dr.-Ing. Norman Feske
Genode Labs

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