代码段:
#include <functional>
#include <iostream>
class OnExit
{
public:
explicit OnExit(const std::function<void()>& f):f_(f){}
~OnExit(){f_();}
private:
std::function<void()> f_;
};
void finish(const bool& details)
{
std::cout << "foo finished with " << std::boolalpha << details << std::endl;
}
int foo(int i)
{
bool details = false;
OnExit action{std::bind(&finish, std::cref(details))};
if (i < 0)
{
throw 0;
}
if (i < 10)
{
return i;
}
int result = i*6;
details = true;
if (i < 100)
{
return result + 5;
}
details = false;
return result*result;
}
int main()
{
std::cout << foo(5) << std::endl;
std::cout << foo(20) << std::endl;
try
{
std::cout << foo(-1) << std::endl;
}
catch (...)
{
std::cout << "exception" << std::endl;
}
std::cout << foo(120) << std::endl;
}
因此,每当程序离开foo()范围时,都会调用函数finish()。变量&#39;细节的价值&#39;阅读并打印。
但......铿锵有力的输出:
2 warnings generated.
<<path>>/neverused.cpp:33:5: warning: Value stored to 'details' is never read [clang-analyzer-deadcode.DeadStores]
details = true;
^
<<path>>/neverused.cpp:33:5: note: Value stored to 'details' is never read
details = true;
^
<<path>>/neverused.cpp:40:5: warning: Value stored to 'details' is never read [clang-analyzer-deadcode.DeadStores]
details = false;
^
<<path>>/neverused.cpp:40:5: note: Value stored to 'details' is never read
details = false;
^
将std :: bind更改为lambda后,没有警告。 我的问题是:bind和/或reference_wrapper背后的魔力是什么以及为什么clang-tidy不理解它?