3 ms·

Foul depths of hell? I've never programmed in C or C++, but this seems to me to be a map from strings to vectors of strings. Reads easily. I don't like the :: n

Foul depths of hell? I've never programmed in C or C++, but this seems to me to be a map from strings to vectors of strings. Reads easily. I don't like the :: namespace separator, but what can you do...

abrichr 14y ago
but what can you do... using namespace std; map<string, vector<string>> foo;
- luser001 14y ago
  I used to do this. But then I realized I would be importing all symbols from std into my code. Including ones that might get defined in the future (similar to python's 'from foo import *'), which might conflict with some of my own symbols. Hence, I now implicitly import each symbol I need with something like 'using std::map;' (similar to python's 'from foo import bar, bar2'). I've found that the 'using' statement can be used even inside a function to restrict the importation to just a single function. FYI.
  - anonymouz 14y ago
    That's good advice. But even when importing all of std, at least namespace collisions in C++ will result in some somewhat sane compiler error. I not so fondly remember a day hunting down a cryptic C compiler error coming from some header that had #define F1 ..., replacing F1 in my file by some cryptic mess...
  - abrichr 14y ago
    Interesting; I never thought of that analogy to Python. I've just had it drilled into my head from everything I've ever read about C++ that "using namespace std" is terrible, and I shouldn't use it. Great advice. Thanks!
    - yuushi 14y ago
      Except the analogy to Python lacks one critical point: C++ headers and Python imports do not work in nearly the same way. Do not EVER use a "using namespace <foo>" in a header file; any code that #include's such a header will pull this in. In .cpp files it's ok (and almost required if you're using boost, unless you want boost::foo:bar::type everywhere). It still requires a bit of thought, though.
- popee 14y ago
  It's ugly to see shift operator here? :-)
  - Saavedro 14y ago
    Unless you're on C++11 you'll be required to shove a space in there to get it to compile anyway ;)

abrichr 14y ago

but what can you do... using namespace std; map<string, vector<string>> foo;

luser001 14y ago
I used to do this. But then I realized I would be importing all symbols from std into my code. Including ones that might get defined in the future (similar to python's 'from foo import *'), which might conflict with some of my own symbols. Hence, I now implicitly import each symbol I need with something like 'using std::map;' (similar to python's 'from foo import bar, bar2'). I've found that the 'using' statement can be used even inside a function to restrict the importation to just a single function. FYI.
- anonymouz 14y ago
  That's good advice. But even when importing all of std, at least namespace collisions in C++ will result in some somewhat sane compiler error. I not so fondly remember a day hunting down a cryptic C compiler error coming from some header that had #define F1 ..., replacing F1 in my file by some cryptic mess...
- abrichr 14y ago
  Interesting; I never thought of that analogy to Python. I've just had it drilled into my head from everything I've ever read about C++ that "using namespace std" is terrible, and I shouldn't use it. Great advice. Thanks!
  - yuushi 14y ago
    Except the analogy to Python lacks one critical point: C++ headers and Python imports do not work in nearly the same way. Do not EVER use a "using namespace <foo>" in a header file; any code that #include's such a header will pull this in. In .cpp files it's ok (and almost required if you're using boost, unless you want boost::foo:bar::type everywhere). It still requires a bit of thought, though.
popee 14y ago
It's ugly to see shift operator here? :-)
- Saavedro 14y ago
  Unless you're on C++11 you'll be required to shove a space in there to get it to compile anyway ;)