内环

Question

匿名结构下面的代码编译罚款与G ++

#include <iostream> 
using namespace std; 

int main() 
{ 
    for (struct { int i; double j; } x = {0,0}; x.i < 10; ++x.i, x.j+=.1) 
    { 
     std::cout << x.i << " " << x.j << '\n'; 
    } 
} 

但随着MSVC2005我得到的错误

error C2332: 'struct' : missing tag name 
error C2143: syntax error : missing ')' before '{' 
warning C4094: untagged 'struct' declared no symbols 
error C2059: syntax error : 'empty declaration' 
error C2143: syntax error : missing ';' before ')' 
error C2143: syntax error : missing ';' before ')' 
error C2065: 'x' : undeclared identifier 
error C2059: syntax error : '{' 
error C2143: syntax error : missing ';' before '{' 
error C2143: syntax error : missing ';' before '}' 
error C2228: left of '.i' must have class/struct/union 
1>  type is ''unknown-type'' 
error C2228: left of '.i' must have class/struct/union 
1>  type is ''unknown-type'' 
error C2228: left of '.j' must have class/struct/union 
1>  type is ''unknown-type'' 
error C2059: syntax error : ')' 
error C2143: syntax error : missing ';' before '{' 
error C2228: left of '.i' must have class/struct/union 
1>  type is ''unknown-type'' 
error C2228: left of '.j' must have class/struct/union 
1>  type is ''unknown-type'' 

我想知道，如果匿名结构内循环是一种“延伸”或语言功能和MSC2005是否缺少它？

Answer 1

这是一个bug in msvc。不幸的是，它们的优先级列表并不高。