Que signifient ces erreurs?

Question

Je suis relativement nouveau en C++, donc je glapis quand je vois ces modèles monstrueux impliquant des erreurs.

Voici mon code:

#include "scene.hpp" 
#include <map> 
#include <vector> 
#include <string> 
#include <algorithm> 
#include <functional> 

// projects a ray from the eyepoint through (x, y) in the image plane 
Ray Camera::project_ray(int x, int y){ 
} 

class scene_parser{ 
public: 
    class unimplemented_exception {}; 
    class unknown_command_exception {}; 
    class malformed_command_exception {}; 

    scene_parser(Scene &s); 
    void parse(const std::string &filename); 
private: 
    PixelBufferPTR current_texture; 
    Colour current_material_colour; 
    Material current_material; 

    typedef void (scene_parser::*parsefunc)(std::vector<std::string>); 
    std::map<std::string, parsefunc> funcMap; 
    void init_funcMap(); 
    void apply_func(const std::vector<std::string> &line); 

    // methods which parse the scene file 
    // they each receive a line of the file, tokenized on whitespace 
    void camera_from(std::vector<std::string> line); 
    void camera_target(std::vector<std::string> line); 
    void camera_forw(std::vector<std::string> line); 
    void camera_up(std::vector<std::string> line); 
    void camera_angle(std::vector<std::string> line); 
    void camera_resolution(std::vector<std::string> line); 

    void sphere(std::vector<std::string> line); 
    void tsphere(std::vector<std::string> line); 
    void texture(std::vector<std::string> line); 
    void mesh(std::vector<std::string> line) {throw unimplemented_exception();} 

    void background(std::vector<std::string> line); 
    void ambient_light(std::vector<std::string> line); 
    void parallel_light(std::vector<std::string> line); 
    void point_light(std::vector<std::string> line); 
    void spot_light(std::vector<std::string> line) {throw unimplemented_exception();} 
    void material(std::vector<std::string> line); 

    void render(std::vector<std::string> line); 
    void trace_depth(std::vector<std::string> line); 
}; 

scene_parser::scene_parser(Scene &s) : current_material_colour(0, 0, 0), current_material(0, 0, 0, 0, 0) { 
    init_funcMap(); 
} 

void scene_parser::init_funcMap(){ 
    funcMap["camera_from"] = &scene_parser::camera_from; 
    funcMap["camera_target"] = &scene_parser::camera_target; 
    funcMap["camera_forw"] = &scene_parser::camera_forw; 
    funcMap["camera_up"] = &scene_parser::camera_up; 
    funcMap["camera_angle"] = &scene_parser::camera_angle; 
    funcMap["camera_resolution"] = &scene_parser::camera_resolution; 
    funcMap["sphere"] = &scene_parser::sphere; 
    funcMap["tsphere"] = &scene_parser::tsphere; 
    funcMap["texture"] = &scene_parser::texture; 
    funcMap["mesh"] = &scene_parser::mesh; 
    funcMap["background"] = &scene_parser::background; 
    funcMap["ambient_light"] = &scene_parser::ambient_light; 
    funcMap["parallel_light"] = &scene_parser::parallel_light; 
    funcMap["point_light"] = &scene_parser::point_light; 
    funcMap["spot_light"] = &scene_parser::spot_light; 
    funcMap["material"] = &scene_parser::material; 
    funcMap["render"] = &scene_parser::render; 
    funcMap["trace_depth"] = &scene_parser::trace_depth; 
} 

void scene_parser::apply_func(const std::vector<std::string> &line){ 
    if(line.size() != 0){ 
    std::map<std::string, parsefunc>::iterator it = funcMap.find(line[0]); 
    if(it == funcMap.end()) throw unknown_command_exception(); 
    else{ 
     parsefunc f = it->second; 
     this->*f(line); //line 86 
    } 
    } 
} 

void scene_parser::parse(const std::string &filename){ 
    std::vector<std::string> lines = tokenize_string(file_to_string(filename), "\n"); 

    std::vector<std::vector<std::string> > tokenized_lines; 
    tokenized_lines.resize(lines.size()); 

    std::transform(lines.begin(), lines.end(), tokenized_lines.begin(), tokenized_lines.end(), std::bind2nd(std::ptr_fun(tokenize_string), std::string(" "))); //line 97 

    std::for_each(tokenized_lines.begin(), tokenized_lines.end(), std::mem_fun(&scene_parser::apply_func)); //line 99 
} 

et cela est tokenize_string

std::vector<std::string> tokenize_string(const std::string &s, const std::string &split_chars); 

et voici les erreurs:

Scene.cpp: In member function ‘void scene_parser::apply_func(const std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&)’: 
Scene.cpp:86: error: must use ‘.*’ or ‘->*’ to call pointer-to-member function in ‘f (...)’, e.g. ‘(... ->* f) (...)’ 
In file included from /usr/include/c++/4.4/bits/stl_function.h:712, 
       from /usr/include/c++/4.4/memory:66, 
       from light.hpp:4, 
       from Scene.hpp:4, 
       from Scene.cpp:1: 
/usr/include/c++/4.4/backward/binders.h: At global scope: 
/usr/include/c++/4.4/backward/binders.h: In instantiation of ‘std::binder2nd<std::pointer_to_binary_function<const std::string&, const std::string&, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >’: 
Scene.cpp:97: instantiated from here 
/usr/include/c++/4.4/backward/binders.h:152: error: ‘typename _Operation::result_type std::binder2nd<_Operation>::operator()(typename _Operation::first_argument_type&) const [with _Operation = std::pointer_to_binary_function<const std::string&, const std::string&, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >]’ cannot be overloaded 
/usr/include/c++/4.4/backward/binders.h:146: error: with ‘typename _Operation::result_type std::binder2nd<_Operation>::operator()(const typename _Operation::first_argument_type&) const [with _Operation = std::pointer_to_binary_function<const std::string&, const std::string&, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >]’ 
In file included from /usr/include/c++/4.4/algorithm:62, 
       from Scene.cpp:5: 
/usr/include/c++/4.4/bits/stl_algo.h: In function ‘_OIter std::transform(_IIter1, _IIter1, _IIter2, _OIter, _BinaryOperation) [with _IIter1 = __gnu_cxx::__normal_iterator<std::basic_string<char, std::char_traits<char>, std::allocator<char> >*, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, _IIter2 = __gnu_cxx::__normal_iterator<std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >*, std::vector<std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, std::allocator<std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > >, _OIter = __gnu_cxx::__normal_iterator<std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >*, std::vector<std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, std::allocator<std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > >, _BinaryOperation = std::binder2nd<std::pointer_to_binary_function<const std::string&, const std::string&, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >]’: 
Scene.cpp:97: instantiated from here 
/usr/include/c++/4.4/bits/stl_algo.h:4741: error: no match for call to ‘(std::binder2nd<std::pointer_to_binary_function<const std::string&, const std::string&, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >) (std::basic_string<char, std::char_traits<char>, std::allocator<char> >&, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&)’ 
/usr/include/c++/4.4/backward/binders.h:146: note: candidates are: typename _Operation::result_type std::binder2nd<_Operation>::operator()(const typename _Operation::first_argument_type&) const [with _Operation = std::pointer_to_binary_function<const std::string&, const std::string&, std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >] 
/usr/include/c++/4.4/bits/stl_algo.h: In function ‘_Funct std::for_each(_IIter, _IIter, _Funct) [with _IIter = __gnu_cxx::__normal_iterator<std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >*, std::vector<std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, std::allocator<std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > >, _Funct = std::mem_fun1_t<void, scene_parser, const std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&>]’: 
Scene.cpp:99: instantiated from here 
/usr/include/c++/4.4/bits/stl_algo.h:4200: error: no match for call to ‘(std::mem_fun1_t<void, scene_parser, const std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&>) (std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&)’ 
/usr/include/c++/4.4/bits/stl_function.h:604: note: candidates are: _Ret std::mem_fun1_t<_Ret, _Tp, _Arg>::operator()(_Tp*, _Arg) const [with _Ret = void, _Tp = scene_parser, _Arg = const std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&] 

Il a été compilé avec gcc 4.4 sur Ubuntu 10.10.

Je serais reconnaissant pour toute idée.

Answer 1

Scene.cpp: In member function ‘void scene_parser::apply_func(const std::vector<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&)’: 
Scene.cpp:86: error: must use ‘.*’ or ‘->*’ to call pointer-to-member function in ‘f (...)’, e.g. ‘(... ->* f) (...)’ 

Notez la dernière partie de la deuxième ligne. Il vous suffit d'utiliser des parenthèses pointeurs membres-à-fonctions (PTMFs):

void scene_parser::apply_func(const std::vector<std::string> &line) { 
    if (line.size() != 0) { 
    std::map<std::string, parsefunc>::iterator it = funcMap.find(line[0]); 
    if (it == funcMap.end()) throw unknown_command_exception(); 
    else { 
     parsefunc f = it->second; 
     (this->*f)(line); // line 86 (fixed) 
    } 
    } 
} 

Je voudrais simplement utiliser un « normal » pour la boucle aux autres erreurs « corriger »; il est regrettable que les erreurs de modèle peuvent être si méchant et je déteste aussi.

std::vector<std::vector<std::string> > tokenized_lines; 
tokenized_lines.reserve(lines.size()); 
// c++0x: for (auto const &x : lines) { 
for (std::vector<std::string>::const_iterator x = lines.begin(); x != lines.end(); ++x) { 
    tokenized_lines.push_back(tokenize_string(*x), " "); // no dereference in 0x 
    tokenized_lines.back().apply_func(); 
}