Most used parts of Boost [closed]

Answer 1

I like how you can supply your own destructor for shared_ptr.
This means, for example, you can use it with FILE* and get it to close the file for you.
eg

void safeclose(FILE*fp) {
    if(fp) {
        fclose(fp);
    }
}
void some_fn() {
    boost::shared_ptr fp( fopen(myfilename, "a+t"), safeclose );
    //body of the function, and when ever it exits the file gets closed
    fprintf( fp.get(), "a message\n" );
}