STL Filter - script for laconic STL errors

STL is renowned for its ability to fill screen space meters with error messages. Tired of looking at the screen and seeing pearls like:



testmap.cpp:25: error: no matching function for call to 'std::map<int, double, std::less, std::allocator<std::pair<const int, double> > >::map(int, int, int)'

/usr/include/c++/4.3/bits/stl_map.h:175: note: candidates are: std::map<_Key, _Tp, _Compare, _Alloc>::map(const std::map<_Key, _Tp, _Compare, _Alloc>&) [with _Key = int, _Tp = double, _Compare = std::less, _Alloc = std::allocator<std::pair<const int, double> >]

/usr/include/c++/4.3/bits/stl_map.h:165: note: std::map<_Key, _Tp, _Compare, _Alloc>::map(const _Compare&, const _Alloc&) [with _Key = int, _Tp = double, _Compare = std::less, _Alloc = std::allocator<std::pair<const int, double> >]





Well, a couple more dozen lines.





')

The solution to the problem of long errors is to use STL output filters. About one such filter, stlfilt , told Scott Meyers in his book Effective STL.

Usage example

We have a code with errors in using std :: map:

#include <iostream>

#include <map>

#include <algorithm>

#include <cmath>

using namespace std;



const int values[] = { 1,2,3,4,5 };

const int NVALS = sizeof values / sizeof ( int );



struct intComp: public binary_function< int , int , bool >

{

bool operator ()( int a, int b) const

{

return a < b;

}

};



int main()

{

using namespace std;



typedef map< int , double > valmap;

typedef map< int *, double *> pmap;



valmap m2(1,2,3);

pmap m3(1,2,3);

map< int , double , intComp> valmap3;



valmap m;

pmap p;



for ( int i = 0; i < NVALS; i++)

{

m.insert(make_pair(values[i], pow(values[i], .5)));

valmap3.insert(0);

}



valmap::iterator it = 100;

valmap::const_iterator cit = 100;



m.insert(1,2);

m.insert(make_pair(36, 10.57)); // fine, more convenient

m.insert(m.end(), make_pair(40, 2.29)); // also fine

return 0;

}



* This source code was highlighted with Source Code Highlighter .

instead of g ++ testmap.cpp, we run gfilt testmap.cpp. Result:

testmap.cpp: In function 'int main()':

testmap.cpp:25: error: No match for 'map<int, double>::map(int, int, int)'

testmap.cpp:26: error: No match for 'map<int *, double *>::map(int, int,

int)'

testmap.cpp:35: error: No match for 'map<int, double, intComp>::insert(

int)'

testmap.cpp:38: error: conversion from 'int' to non-scalar type 'gen_map<

int, double>::iterator' requested

testmap.cpp:39: error: conversion from 'int' to non-scalar type 'gen_map<

int, double>::const_iterator' requested

stl_tree.h: In member function 'void map<

int, double>::_M_insert_unique(_II, _II)':

[STL Decryptor: Suppressed 1 more STL standard header message]

testmap.cpp:41: instantiated from here

stl_tree.h:1295: error: invalid type argument of 'unary *'

In my opinion, it looks much nicer.

Installation

Installation and setup is simple:

• download STLFilt
• unpack archive
• in the gfilt shell script write COMPILER = g ++. I still do not like the use of less in the output, remove it from the variable PAGER.
• Everything, now the shell transfers all g ++ keys, accepts error information from it. parses it and gives it to us.