danicoin/external/glim/raii.hpp
Thomas Winget 90d6f8bf62 Adding libglim as an external library
libglim is an Apache-licensed C++ wrapper for lmdb, and rather than
rolling our own it seems prudent to use it.

Note: lmdb is not included in it, and unless something happens as did
with libunbound, should be installed via each OS' package manager or
equivalent.
2015-01-04 18:41:44 -08:00

34 lines
1.3 KiB
C++

#include <functional>
namespace glim {
// http://stackoverflow.com/questions/2121607/any-raii-template-in-boost-or-c0x/
/// RAII helper. Keeps the functor and runs it in the destructor.
/// Example: \code auto unmap = raiiFun ([&]() {munmap (fd, size);}); \endcode
template<typename Fun> struct RAIIFun {
Fun _fun;
RAIIFun (RAIIFun&&) = default;
RAIIFun (const RAIIFun&) = default;
template<typename FunArg> RAIIFun (FunArg&& fun): _fun (std::forward<Fun> (fun)) {}
~RAIIFun() {_fun();}
};
/// The idea to name it `finally` comes from http://www.codeproject.com/Tips/476970/finally-clause-in-Cplusplus.
/// Example: \code finally unmap ([&]() {munmap (fd, size);}); \endcode
typedef RAIIFun<std::function<void(void)>> finally;
/// Runs the given functor when going out of scope.
/// Example: \code
/// auto closeFd = raiiFun ([&]() {close (fd);});
/// auto unmap = raiiFun ([&]() {munmap (fd, size);});
/// \endcode
template<typename Fun> RAIIFun<Fun> raiiFun (const Fun& fun) {return RAIIFun<Fun> (fun);}
/// Runs the given functor when going out of scope.
/// Example: \code
/// auto closeFd = raiiFun ([&]() {close (fd);});
/// auto unmap = raiiFun ([&]() {munmap (fd, size);});
/// \endcode
template<typename Fun> RAIIFun<Fun> raiiFun (Fun&& fun) {return RAIIFun<Fun> (std::move (fun));}
}