Unknown type name error when inserting into unordered_map

I have a single file called main.cpp where I am trying to declare an unordered_map as shown below.

std::unordered_map<std::string, std::set<int>> firstSets;

I then try to insert a new (key, value) pair into the map as follows.

std::string decl = "decl";std::set<int> declFirstSet = {VOID_TOK, INT_TOK, FLOAT_TOK, BOOL_TOK};firstSets[decl] = declFirstSet;

When I do this I get the following compiler error.

C++ requires a type specifier for all declarations

firstSets[decl] = declFirstSet;

size of array has non-integer type 'std::string' (aka 'basic_string')

firstSets[decl] = declFirstSet;

So it seems to think I am declaring 'firstSets' when I am actually tring to insert into it. And it seems to treat 'firstSets' as an array instead of an unordered_map. How do I fix this?