mosesdecoder/util/scoped.hh
2014-10-08 08:42:53 -04:00

110 lines
3.2 KiB
C++

#ifndef UTIL_SCOPED_H
#define UTIL_SCOPED_H
/* Other scoped objects in the style of scoped_ptr. */
#include "util/exception.hh"
#include <cstddef>
#include <cstdlib>
namespace util {
class MallocException : public ErrnoException {
public:
explicit MallocException(std::size_t requested) throw();
~MallocException() throw();
};
void *MallocOrThrow(std::size_t requested);
void *CallocOrThrow(std::size_t requested);
/* Unfortunately, defining the operator* for void * makes the compiler complain.
* So scoped is specialized to void. This includes the functionality common to
* both, namely everything except reference.
*/
template <class T, class Closer> class scoped_base {
public:
explicit scoped_base(T *p = NULL) : p_(p) {}
~scoped_base() { Closer::Close(p_); }
void reset(T *p = NULL) {
scoped_base other(p_);
p_ = p;
}
T *get() { return p_; }
const T *get() const { return p_; }
T *operator->() { return p_; }
const T *operator->() const { return p_; }
T *release() {
T *ret = p_;
p_ = NULL;
return ret;
}
protected:
T *p_;
private:
scoped_base(const scoped_base &);
scoped_base &operator=(const scoped_base &);
};
template <class T, class Closer> class scoped : public scoped_base<T, Closer> {
public:
explicit scoped(T *p = NULL) : scoped_base<T, Closer>(p) {}
T &operator*() { return *scoped_base<T, Closer>::p_; }
const T&operator*() const { return *scoped_base<T, Closer>::p_; }
};
template <class Closer> class scoped<void, Closer> : public scoped_base<void, Closer> {
public:
explicit scoped(void *p = NULL) : scoped_base<void, Closer>(p) {}
};
/* Closer for c functions like std::free and cmph cleanup functions */
template <class T, void (*clean)(T*)> struct scoped_c_forward {
static void Close(T *p) { clean(p); }
};
// Call a C function to delete stuff
template <class T, void (*clean)(T*)> class scoped_c : public scoped<T, scoped_c_forward<T, clean> > {
public:
explicit scoped_c(T *p = NULL) : scoped<T, scoped_c_forward<T, clean> >(p) {}
};
class scoped_malloc : public scoped_c<void, std::free> {
public:
explicit scoped_malloc(void *p = NULL) : scoped_c<void, std::free>(p) {}
void call_realloc(std::size_t to);
};
/* scoped_array using delete[] */
struct scoped_delete_array_forward {
template <class T> static void Close(T *p) { delete [] p; }
};
// Hat tip to boost.
template <class T> class scoped_array : public scoped<T, scoped_delete_array_forward> {
public:
explicit scoped_array(T *p = NULL) : scoped<T, scoped_delete_array_forward>(p) {}
T &operator[](std::size_t idx) { return scoped<T, scoped_delete_array_forward>::p_[idx]; }
const T &operator[](std::size_t idx) const { return scoped<T, scoped_delete_array_forward>::p_[idx]; }
};
/* scoped_ptr using delete. If only there were a template typedef. */
struct scoped_delete_forward {
template <class T> static void Close(T *p) { delete p; }
};
template <class T> class scoped_ptr : public scoped<T, scoped_delete_forward> {
public:
explicit scoped_ptr(T *p = NULL) : scoped<T, scoped_delete_forward>(p) {}
};
} // namespace util
#endif // UTIL_SCOPED_H