标准C 11是否保证在开始执行函数之前创建了所有3个临时对象？
即使临时对象传递为：
>对象
> rvalue-reference
>仅传递临时对象的成员
#include <iostream>
using namespace std;
struct T {
T() { std::cout << "T created \n"; }
int val = 0;
~T() { std::cout << "T destroyed \n"; }
};
void function(T t_obj,T &&t,int &&val) {
std::cout << "func-start \n";
std::cout << t_obj.val << "," << t.val << "," << val << std::endl;
std::cout << "func-end \n";
}
int main() {
function(T(),T(),T().val);
return 0;
}
输出：
T created T created T created func-start 0,0 func-end T destroyed T destroyed T destroyed
工作草案,编程语言标准C 2016-07-12：http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/n4606.pdf
§ 5.2.2 Function call
§ 5.2.2
1 A function call is a postfix
expression followed by parentheses containing a possibly empty,
comma-separated list of initializer-clauses which constitute the
arguments to the function.
但是可以在func-start之后创建T中的任何一个吗？
或者有没有办法将参数作为g / r / l / x / pr-value传递,以便在创建临时对象之前启动函数？
解决方法
[intro.execution]/16：
When calling a function (whether or not the function is inline),every value computation and side effect associated with any argument expression,or with the postfix expression designating the called function,is sequenced before execution of every expression or statement in the body of the called function.
