g++ variable size array no warning?

c++, g++, heap-memory, memory

Solution

ISO C++ disallows the use of variable length arrays, which `g++` happily tells you if you increase the strictness of it by passing it the `-pedantic` flag.

Using `-pedantic` will issue a warning about things breaking the standard. If you want `g++` to issue an error and with this refuse compilation because of such things; use `-pedantic-errors`.

g++ -Wall -pedantic -std=c++11 apa.cpp

apa.cpp: In function ‘int main(int, char**)’:
apa.cpp:8:13: warning: ISO C++ forbids variable length array ‘ints’ [-Wvla]
   int ints[a];
             ^
apa.cpp:8:7: warning: unused variable ‘ints’ [-Wunused-variable]
   int ints[a];
       ^

Problem

``` int a; cin >> a; int ints[a]; ``` Why does this not throw any kind of warning while compiling? How do I know when this array thing is actually using the heap or the stack? `g++ -std=c++11 -Wall *.cpp -o main`

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