c++ - Unnamed struct declaration inside for loop initialization statement -

in 1 of thread, had seen usage of unnamed struct acting placeholder multiple variables of different types inside loop:

for example:

for(struct {       int i;       double d;       char c;     } obj = { 1, 2.2, 'c' };     obj.i < 10;     ++obj.i) {   ... } 

this compiles fine g++.
standard c++03 syntax?

you can use unnamed struct anywhere can use struct - difference doesn't name can used somewhere else. can declare new type anywhere can use type, pretty much. may not particularly meaningful in places, that's matter.

i wouldn't recommend this, other in special cases, it's valid.