Wonderland

// assign_aTest.cpp : Defines the entry point for the console application.
//

#include “stdafx.h”

#include “boost/spirit.hpp”
#include “boost/spirit/actor/ref_actor.hpp”

using namespace boost;
using namespace boost::spirit;

#include

struct MyParser
: public grammar
{
mutable int m_i;

/// Constructor
MyParser()
{
}

/// Grammar definition
template
struct definition
{
definition(MyParser const& self)
{
test = (ch_p(L’@'))
[assign_a(self.m_i, 100)];
}

rule test;

// Start rule
rule const& start() const { return test; }
};
};

struct MyParser2
: public grammar
{
mutable int m_i;

static const int s_i = 100;

/// Constructor
MyParser2()
{
}

/// Grammar definition
template
struct definition
{
definition(MyParser2 const& self)
{
test = (ch_p(L’@'))
[assign_a(self.m_i, s_i)];
}

rule test;

// Start rule
rule const& start() const { return test; }
};
};

int _tmain(int argc, _TCHAR* argv[])
{
struct MyParser pa;
pa.m_i = 0;
parse(L”@”, pa);

struct MyParser2 pa2;
pa2.m_i = 0;
parse(L”@”, pa2);

std::cout<<"Parse1: "<<pa.m_i<<std::endl;
std::cout<<"Parse2: "<<pa2.m_i<<std::endl;

std::cin.get();
return 0;
}

VC在函数中将常数值赋给一个常引用，会导致出函数有效区域后此引用的无效，为一个不确定值。
更一般的测试例程：

// RefTst.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include
#include

using namespace std;

class A
{
private:
const int& m_i;

public:
A(const int& i)
: m_i(i)
{
}

void PrintI()
{
cout<<"I: "<<m_i<<endl;
const int* p = &m_i;
cout<<"P: "<<p<<endl;
}
};

A* GetA()
{
A* pA = new A(123456789);
pA->PrintI();
return pA;
}

void Print(A* pA)
{
int i = 54321;
__int64 j = 13328703583;
pA->PrintI();
}

int _tmain(int argc, _TCHAR* argv[])
{
A* pA = NULL;
pA = GetA();
pA->PrintI();
Print(pA);
delete pA;
cin.get();
return 0;
}