scanf on an istream object

Question

NOTE: I\'ve seen the post What is the cin analougus of scanf formatted input? before asking the question and the post doesn\'t solve my problem here. The post seeks for C++-

Answer 1

I do not recommend you to mix C++ input output and C input output. No that they are really incompatible but they could just plain interoperate wrong.

For example Oracle docs recommend not to mix it http://www.oracle.com/technetwork/articles/servers-storage-dev/mixingcandcpluspluscode-305840.html

But no one stops you from reading data into the buffer and parsing it with standard c functions like sscanf.

...
string curString;
int a, b;
...

std::getline(inputStream, curString);

int sscanfResult == sscanf(curString.cstr(), "%d:%d", &a, &b);

if (2 != sscanfResult)
   throw "error";
...

But it won't help in some situations when your stream is just one long contiguous sequence of symbols(like some string turned into memory stream).

Making your own fscanf from scratch or porting(?) the original CRT function actually isn't the worst possible idea. Just make sure you have tested it thoroughly(low level custom char manipulation was always a source of pain in C).

I've never really tried the boost\spirit and such parsing infrastructure could really be an overkill for your project. But boost libraries are usually well tested and designed. You could at least try to use it.