94 lines
3.2 KiB
C++
94 lines
3.2 KiB
C++
|
// Copyright 2011 Google Inc.
|
||
|
|
// All rights reserved.
|
||
|
|
//
|
||
|
|
// Redistribution and use in source and binary forms, with or without
|
||
|
|
// modification, are permitted provided that the following conditions are
|
||
|
|
// met:
|
||
|
|
//
|
||
|
|
// * Redistributions of source code must retain the above copyright
|
||
|
|
// notice, this list of conditions and the following disclaimer.
|
||
|
|
// * Redistributions in binary form must reproduce the above copyright
|
||
|
|
// notice, this list of conditions and the following disclaimer in the
|
||
|
|
// documentation and/or other materials provided with the distribution.
|
||
|
|
// * Neither the name of Google Inc. nor the names of its contributors
|
||
|
|
// may be used to endorse or promote products derived from this software
|
||
|
|
// without specific prior written permission.
|
||
|
|
//
|
||
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||
|
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||
|
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
||
|
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
||
|
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
||
|
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
||
|
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
||
|
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
||
|
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||
|
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
||
|
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
|
||
|
|
/// \file stack_cleaner.hpp
|
||
|
|
/// Provides the stack_cleaner class.
|
||
|
|
|
||
|
|
#if !defined(LUTOK_STACK_CLEANER_HPP)
|
||
|
|
#define LUTOK_STACK_CLEANER_HPP
|
||
|
|
|
||
|
|
#include <memory>
|
||
|
|
|
||
|
|
#include <lutok/state.hpp>
|
||
|
|
|
||
|
|
namespace lutok {
|
||
|
|
|
||
|
|
|
||
|
|
/// A RAII model for values on the Lua stack.
|
||
|
|
///
|
||
|
|
/// At creation time, the object records the current depth of the Lua stack and,
|
||
|
|
/// during destruction, restores the recorded depth by popping as many stack
|
||
|
|
/// entries as required. As a corollary, the stack can only grow during the
|
||
|
|
/// lifetime of a stack_cleaner object (or shrink, but cannot become shorter
|
||
|
|
/// than the depth recorded at creation time).
|
||
|
|
///
|
||
|
|
/// Use this class as follows:
|
||
|
|
///
|
||
|
|
/// state s;
|
||
|
|
/// {
|
||
|
|
/// stack_cleaner cleaner1(s);
|
||
|
|
/// s.push_integer(3);
|
||
|
|
/// s.push_integer(5);
|
||
|
|
/// ... do stuff here ...
|
||
|
|
/// for (...) {
|
||
|
|
/// stack_cleaner cleaner2(s);
|
||
|
|
/// s.load_string("...");
|
||
|
|
/// s.pcall(0, 1, 0);
|
||
|
|
/// ... do stuff here ...
|
||
|
|
/// }
|
||
|
|
/// // cleaner2 destroyed; the result of pcall is gone.
|
||
|
|
/// }
|
||
|
|
/// // cleaner1 destroyed; the integers 3 and 5 are gone.
|
||
|
|
///
|
||
|
|
/// You must give a name to the instantiated objects even if they cannot be
|
||
|
|
/// accessed later. Otherwise, the instance will be destroyed right away and
|
||
|
|
/// will not have the desired effect.
|
||
|
|
class stack_cleaner {
|
||
|
|
struct impl;
|
||
|
|
|
||
|
|
/// Pointer to the shared internal implementation.
|
||
|
|
std::auto_ptr< impl > _pimpl;
|
||
|
|
|
||
|
|
/// Disallow copies.
|
||
|
|
stack_cleaner(const stack_cleaner&);
|
||
|
|
|
||
|
|
/// Disallow assignment.
|
||
|
|
stack_cleaner& operator=(const stack_cleaner&);
|
||
|
|
|
||
|
|
public:
|
||
|
|
stack_cleaner(state&);
|
||
|
|
~stack_cleaner(void);
|
||
|
|
|
||
|
|
void forget(void);
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
} // namespace lutok
|
||
|
|
|
||
|
|
#endif // !defined(LUTOK_STACK_CLEANER_HPP)
|