Question

I have a cpp file that contains the following:

char const* types[] = { "char", "short", "int", "long", "float", "double", "void"};
std::set<std::string> ReservedWords;
ReservedWords.insert(std::begin(types),std::end(types));

this gives an error missing type specifier - int assumed. Note: C++ does not support default-int

I have read that you can’t write statements in a global scope, is this the case here ?

I don’t completely understand the rule, and would like to know where its best to put this code ? (header file, inside a function etc…)

Answer 1

char const* types[] = { "char", "short", "int", "long", "float", "double", "void"};
std::set<std::string> ReservedWords;
ReservedWords.insert(std::begin(types),std::end(types));

The first two lines here are declarations because they declare variables (types and ReservedWords). The third line is not a declaration, it’s just an expression statement so it’s not legal for it to appear outside a function.

You could do something like:

char const* types[] = { "char", "short", "int", "long", "float", "double", "void"};
std::set<std::string> MakeReservedWords() {
    std::set<std::string> tmp;
    tmp.insert(std::begin(types), std::end(types));
    return tmp;
}

std::set<std::string> ReservedWords(MakeReservedWords());

Given that you are using C++11 you should be able to do this:

std::set<std::string> ReservedWords { "char", "short", "int", "long", "float", "double", "void"};

If your compiler doesn’t support this part of C++11 you will have to settle for something like this (as suggested by @juanchopanza):

char const* types[] = { "char", "short", "int", "long", "float", "double", "void"};
std::set<std::string> ReservedWords(std::begin(types), std::end(types));