nameof_module/example/example.cpp
2021-01-24 08:39:23 +02:00

223 lines
8.2 KiB
C++

// Licensed under the MIT License <http://opensource.org/licenses/MIT>.
// SPDX-License-Identifier: MIT
// Copyright (c) 2018 - 2021 Daniil Goncharov <neargye@gmail.com>.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
#include <nameof.hpp>
#include <iostream>
#include <string>
#include <sstream>
#include <stdexcept>
struct Base { virtual ~Base() = default; };
struct Derived : Base {};
struct SomeStruct {
int somefield = 0;
void SomeMethod1(int i) { somefield = i; }
int SomeMethod2() const { return somefield; }
};
void SomeMethod3() {
std::cout << NAMEOF(SomeMethod3) << " no called!" << std::endl;
}
template <typename T, typename U>
std::string SomeMethod4(U value) {
auto function_name = NAMEOF(SomeMethod4<T, U>).str()
.append("<")
.append(NAMEOF_TYPE(T))
.append(", ")
.append(NAMEOF_TYPE(U))
.append(">(")
.append(NAMEOF_TYPE(U))
.append(" ")
.append(NAMEOF(value).data())
.append(")");
return function_name;
}
template <typename T>
class SomeClass {
public:
void SomeMethod5() const {
std::cout << nameof::nameof_type<T>() << std::endl;
}
template <typename C>
C SomeMethod6() const {
C t{};
std::cout << NAMEOF_TYPE_EXPR(t) << std::endl;
return t;
}
};
struct Long {
struct LL {
int field = 0;
};
LL ll;
};
enum class Color { RED, GREEN, BLUE };
enum AnimalFlags { HasClaws = 1 << 0, CanFly = 1 << 1, EatsFish = 1 << 2, Endangered = 1 << 3 };
SomeStruct structvar;
Long othervar;
SomeStruct* ptrvar = &structvar;
void name_to_chars(const char* name) {
std::cout << name << std::endl;
}
void name_to_string(const std::string& name) {
std::cout << name << std::endl;
}
void name_to_string_view(std::string_view name) {
std::cout << name << std::endl;
}
int main() {
// Compile-time.
constexpr auto name = NAMEOF(structvar);
using namespace std::literals::string_view_literals;
static_assert("structvar"sv == name);
name_to_chars(name.c_str()); // 'structvar'
// or name_to_chars(name.data());
// Note: c_str() return name as null-terminated C string, no memory allocation.
name_to_string(name.str()); // 'structvar'
// Note: str() occure memory allocation to copy name to std::string.
// or name_to_string(std::string{name});
// or name_to_string(static_cast<std::string>(name));
// Note: cast to std::string occure memory allocation to copy name to std::string.
name_to_string_view(name); // 'structvar'
// Note: Implicit cast to std::string_view, no memory allocation.
#if defined(NAMEOF_ENUM_SUPPORTED)
// Nameof enum variable.
auto color = Color::RED;
std::cout << nameof::nameof_enum(color) << std::endl; // 'RED'
std::cout << NAMEOF_ENUM(color) << std::endl; // 'RED'
std::cout << nameof::nameof_enum<Color::GREEN>() << std::endl; // 'GREEN'
// Nameof enum flags.
auto flag = static_cast<AnimalFlags>(AnimalFlags::CanFly | AnimalFlags::EatsFish);
std::cout << nameof::nameof_enum_flag(flag) << std::endl; // 'CanFly|EatsFish'
std::cout << NAMEOF_ENUM_FLAG(flag) << std::endl; // 'CanFly|EatsFish'
#endif
// Nameof.
std::cout << NAMEOF(structvar) << std::endl; // 'structvar'
std::cout << NAMEOF(::structvar) << std::endl; // 'structvar'
std::cout << NAMEOF(structvar.somefield) << std::endl; // 'somefield'
std::cout << NAMEOF((&structvar)->somefield) << std::endl; // 'somefield'
std::cout << NAMEOF(othervar.ll.field) << std::endl; // 'field'
std::cout << NAMEOF(ptrvar) << std::endl; // 'ptrvar
// Nameof function.
std::cout << NAMEOF(&SomeStruct::SomeMethod1) << std::endl; // 'SomeMethod1'
std::cout << NAMEOF(structvar.SomeMethod2()) << std::endl; // 'SomeMethod2'
std::cout << NAMEOF(SomeMethod3) << std::endl; // 'SomeMethod3'
std::cout << NAMEOF(SomeMethod4<int, float>(1.0f)) << std::endl; // 'SomeMethod4'
std::cout << NAMEOF(&SomeClass<int>::SomeMethod5) << std::endl; // 'SomeMethod5'
std::cout << NAMEOF(&SomeClass<int>::SomeMethod6<long int>) << std::endl; // 'SomeMethod6'
// Nameof with template suffix.
std::cout << NAMEOF_FULL(SomeMethod4<int, float>) << std::endl; // 'SomeMethod4<int, float>'
std::cout << NAMEOF_FULL(&SomeClass<int>::SomeMethod6<long int>) << std::endl; // 'SomeMethod6<long int>'
// Nameof type.
std::cout << nameof::nameof_type<const Long::LL&>() << std::endl; // 'Long::LL'
std::cout << NAMEOF_TYPE(const Long::LL&) << std::endl; // 'Long::LL'
std::cout << nameof::nameof_full_type<const Long::LL&>() << std::endl; // 'const Long::LL &'
std::cout << NAMEOF_FULL_TYPE(const Long::LL&) << std::endl; // 'const Long::LL &'
std::cout << NAMEOF_SHORT_TYPE(const Long::LL&) << std::endl; // 'LL'
std::cout << NAMEOF_SHORT_TYPE(const SomeClass<int>&) << std::endl; // 'SomeClass'
// Nameof variable type.
std::cout << nameof::nameof_type<decltype(structvar)>() << std::endl; // 'SomeStruct'
std::cout << NAMEOF_TYPE_EXPR(structvar) << std::endl; // 'SomeStruct'
std::cout << NAMEOF_TYPE_EXPR(std::declval<const SomeClass<int>>()) << std::endl; // 'SomeClass<int>'
std::cout << NAMEOF_FULL_TYPE_EXPR(std::declval<const SomeClass<int>>()) << std::endl; // 'const SomeClass<int> &&'
std::cout << NAMEOF_SHORT_TYPE_EXPR(std::declval<const SomeClass<int>>()) << std::endl; // 'SomeClass'
// Nameof macro.
std::cout << NAMEOF(__LINE__) << std::endl; // '__LINE__'
// Nameof raw.
std::cout << NAMEOF_RAW(structvar.somefield) << std::endl; // 'structvar.somefield'
std::cout << NAMEOF_RAW(&SomeStruct::SomeMethod1) << std::endl; // '&SomeStruct::SomeMethod1'
#if defined(NAMEOF_TYPE_RTTI_SUPPORTED)
// Nameof type using RTTI.
Base* ptr = new Derived();
std::cout << NAMEOF_TYPE_RTTI(ptr) << std::endl; // 'Base *'
std::cout << NAMEOF_TYPE_RTTI(*ptr) << std::endl; // 'Derived'
#endif
// Some more complex example.
std::cout << SomeMethod4<int>(structvar) << std::endl; // 'SomeMethod4<int, SomeStruct>(SomeStruct value)'
auto div = [](int x, int y) -> int {
if (y == 0) {
throw std::invalid_argument(NAMEOF(y).str() + " should not be zero!");
}
return x / y;
};
try {
auto z = div(10, 0);
std::cout << z << std::endl;
} catch (const std::exception& e) {
std::cout << e.what() << std::endl; // 'y should not be zero!'
}
/* Remarks */
#if 0
// This expression does not have name.
std::cout << NAMEOF(ptrvar[0]) << std::endl; // ''
std::cout << NAMEOF(42.0) << std::endl; // ''
std::cout << NAMEOF(42) << std::endl; // ''
std::cout << NAMEOF(42.0_deg) << std::endl; // ''
std::cout << NAMEOF((structvar)) << std::endl; // ''
std::cout << NAMEOF((SomeMethod4<int, float>)(1.0f)) << std::endl; // ''
std::cout << NAMEOF(42, 42, 42) << std::endl; // ''
std::cout << NAMEOF(42 + 42) << std::endl; // ''
std::cout << NAMEOF("Bad case"_string) << std::endl; // ''
std::cout << NAMEOF("Bad case") << std::endl; // ''
std::cout << NAMEOF("somevar.somefield") << std::endl; // ''
std::cout << NAMEOF(42.f) << std::endl; // ''
std::cout << NAMEOF(structvar.somefield++) << std::endl; // ''
std::cout << NAMEOF(std::string{"test"}) << std::endl; // ''
#endif
return 0;
}