This is a continuation of this previous question removing code duplication and user 1201programalarm suggested to use CRTP to resolve my issue. I'm trying to take their advice and when I try to apply it to my Bus class Visual Studio is generating compiler errors...
When I try to do this:
template<size_t BusSize>
class Bus : public Component, ComponentID<Bus> {
I get this error:
>------ Build started: Project: Simulator, Configuration: Debug x64 ------
1>main.cpp
1>c:\***\bus.h(6): error C3203: 'Bus': unspecialized class template can't be used as a template argument for template parameter 'T', expected a real type
1>c:\***\bus.h(49): note: see reference to class template instantiation 'Bus<BusSize>' being compiled
1>Done building project "Simulator.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
And when I try to change it to this:
template<size_t BusSize>
class Bus : public Component, ComponentID<Bus<BusSize>> {
It then gives me these errors:
>------ Build started: Project: Simulator, Configuration: Debug x64 ------
1>main.cpp
1>c:\***\bus.h(11): error C2512: 'ComponentID<Bus<4>>': no appropriate default constructor available
1>c:\***\bus.h(6): note: see declaration of 'ComponentID<Bus<4>>'
1>c:\***\bus.h(11): note: while compiling class template member function 'Bus<4>::Bus(const std::string &)'
1>c:\***\main.cpp(10): note: see reference to function template instantiation 'Bus<4>::Bus(const std::string &)' being compiled
1>c:\***\main.cpp(10): note: see reference to class template instantiation 'Bus<4>' being compiled
1>c:\***\bus.h(11): error C2614: 'Bus<4>': illegal member initialization: 'ComponentID' is not a base or member
1>Done building project "Simulator.vcxproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
I'm not sure what else to try to resolve these compiler errors...
Here is my source code...
main.cpp
#include <exception>
#include "Bus.h"
int main() {
try {
Wire w1, w2, w3, w4;
std::cout << w1.id() << " " << w2.id() << " " << w3.id() << " "<< w4.id() << "\n\n";
Bus<4> b1;
b1.connect(&w1, 0);
b1.connect(&w2, 1);
b1.connect(&w3, 2);
b1.connect(&w4, 3);
b1.connect(&w1, 1); // Valid Connection: same wire to multiple bus wires
b1.connect(&w1, 0); // Invalid Connection: trying to connect a same wire to the same bus wire multiple times...
std::cout << "\n";
Bus<4> b2;
w1.connect(&w2);
w2.connect(&w3);
w3.connect(&w4);
w4.connect(&w1);
std::cout << "\n";
b2.connect(&b1.wire(0), 0);
b2.connect(&b1.wire(1), 1);
b2.connect(&b1.wire(2), 2);
b2.connect(&b1.wire(3), 3);
std::cout << "\nThese are my connected components:\n";
for( size_t i = 0; i < b2.size(); i++ ) {
for (auto& component : b2.myConnections(i)) {
std::cout << "\t" << component->id() << " has ";
auto connections = component->myConnections();
for (auto& c : connections) {
std::cout << c->id() << " ";
}
std::cout << '\n';
}
std::cout << '\n';
}
} catch (const std::exception& e) {
std::cerr << e.what() << std::endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
Component.h
#pragma once
#include <assert.h>
#include <memory>
#include <array>
#include <list>
#include <iomanip>
#include <iostream>
#include <string>
#include <sstream>
// I added this class template to handle the `ID's` as suggested to remove the code duplication...
template<class T>
class ComponentID {
public:
explicit ComponentID(std::string& id) {
static int i = 0;
std::stringstream strValue;
strValue << std::setw(3) << std::setfill('0') << std::to_string(i++);
id.append("_" + strValue.str());
}
};
class Component {
protected:
std::string id_ = "";
std::list<std::shared_ptr<Component>> components_;
explicit Component(const std::string& id) : id_{ id } {}
public:
virtual ~Component() {}
std::string& id() { return id_; }
void connect(Component* other) {
for (auto& l : components_) {
if (other->id_ == l->id()) {
std::cout << "Component " << other->id_ << " already exists in " << id_ << "!\n";
return;
}
}
components_.push_back( std::make_shared<Component>( *other ) );
std::cout << "Successfully connected " << other->id() << " to " << id_ << "\n";
}
virtual std::list<std::shared_ptr<Component>> myConnections() { return components_; }
virtual void propagate() {};
};
Wire.h
#pragma once
#include "Component.h"
// I added ComponentID as an inherited base,
// I removed the `updateID()` function from this class,
// and I removed the call to it from within the constructor
class Wire : public Component, ComponentID<Wire> {
private:
public:
explicit Wire(const std::string& name = "Wire") : Component(name), ComponentID(id_) {
//updateId();
};
virtual ~Wire() {}
virtual void propagate() override {
return;
}
};
Now, this is where I'm starting to have some issues...
Bus.h
#pragma once
#include "Wire.h"
// I'm trying to do the same as I did in my Wire class through inheritance...
// I also removed the updateID() function and the call to it with the constructor
// However, this is generating a compiler error.
template<size_t BusSize>
class Bus : public Component, ComponentID<Bus> {
private:
std::array<std::shared_ptr<Wire>, BusSize> bus_interface_;
public:
explicit Bus(const std::string& name = "Bus") : Component(name), ComponentID(id_) {
createBus();
}
virtual ~Bus() {}
virtual void propagate() override {
return;
}
void connect(Component* component, size_t index) {
assert(index < BusSize);
assert(component != nullptr);
bus_interface_[index]->connect(component);
std::cout << "\t from " << component->id() << " to " << id_ << "\n";
}
Wire wire(size_t index) {
assert(index < BusSize);
return *bus_interface_[index].get();
}
std::array<std::shared_ptr<Wire>, BusSize> bus() { return bus_interface_; }
std::list<std::shared_ptr<Component>> myConnections(size_t index) {
assert(index < BusSize);
return bus_interface_[index]->myConnections();
}
size_t size() const { return BusSize; }
private:
void createBus() {
size_t i = 0;
for (auto& w : bus_interface_) {
w = std::shared_ptr<Wire>(new Wire);
}
}
};
