I was following this tutorial on GNU compilers found here which does some simple compiling of a "hello world" c++ script "hello.cpp" by doing:
$ g++ -o hello hello.cpp
$ chmod a+x hello
$ ./hello
And it made me realise with the limited knowledge of compiling I have that I sometimes have to specify my output as an executable using "chmod a+x" and sometimes its already an executable without it (which was the case for me when I ran the above).
Is it perhaps a version thing of g++ perhaps?