06/02/15 09:08:44
>>622,623
値型の場合、(1)が無難な気がしてきた。(2)はテンポラリGCポインタなのか...(3)はなんか怪しい...
参照型の場合、(2)しか選択もうない気が、第４の選択肢は危険ぽいし...
ref struct Test{
Test(){}int x;Test(int in_x) :x(in_x){}
static void test(){
System::Collections::Generic::List<int> v;v.Add(1);v.Add(2);v.Add(3); //case1
//cli::array<int>^ v = {1,2,3}; //case2
#define SHOW for each(int i in v){Console::WriteLine(i);}
for each(int i in v){i *= 2;}SHOW;//result->{1,2,3}
for each(int^ p in v){(*p) *= 2;}SHOW;//result->{1,2,3}
//for each(int^% p in v){(*p) *= 2;}SHOW;//danger
for each(int% r in v){r *= 2;}SHOW; //case1->{1,2,3},case2->{2,4,6} -> unsafe code
}
static void test2(){
System::Collections::Generic::List<Test^> v;v.Add(%Test(1));v.Add(%Test(2));v.Add(%Test(3));
//cli::array<Test^>^ v ={ %Test(1),%Test(2),%Test(3) };
#define SHOW2 for each(Test^ t in v){Console::WriteLine(t->x);}
for each(Test^ p in v){(*p).x *= 2;}SHOW2;//result->{2,4,6}
for each(Test^% r in v){(*r).x *= 2;}SHOW2;//result->{4,8,12},case2->{2,4,6} -> unsafe code
}
};