C/C++ : converting std::string to const char* I get the error : left of '.c_str' must have class/struct/union type is 'char *' C# to C++ dll - how to pass strings as In/Out parameters to unmanaged functions that expect a string (LPSTR) as a function parameter. C++ int to str...
nullptr : nullptr; // OK // char *ptr1 = expr ? 0 : nullptr; // Not OK, types are not compatible static_assert(sizeof(NULL) == sizeof(nullptr_t)); Summary by FAQs When was nullptr introduced? C++11 Is nullptr a keyword or an instance of a type std::nullptr_t? Both true ...
template<typenameT>autoget_value(T t) {ifconstexpr (std::is_pointer_v<T>)return*t;// deduces return type to int for T = int*elsereturnt;// deduces return type to int for T = int} IfTis a pointer, the if branch in line 3 will be compiled. If not, the else branch is in ...
Thus, constexpr allows for optimization possibilities where some simple computation might be performed by the compiler. In the example above, Div_Expr() is invoked with arguments that are integral constants 22 and 7. Hence, the compiler is able to compute pi. If the arguments were not constant...
Additionally to the suggestions from TurtleShell, using compilation time comes to my mind. For example in C++, the compiler is able to evaluate "const" and "constexpr" expressions at compile time, meaning it isn't necessary at runtime anymore, effectively decreasing the runtime of your program...
int main() { constexpr int MAXWEIGHT{ 2500 }; int sum = 0, weight = 0; int totalOver{}; // <--- ALWAYS initialize all your variables. cout << "\n" "This elevator can fit a total of 5 people.\n" "Not to exceed 2500 pounds.\n\n"; for (int i = 0; i < 5; i++)...
ReSharper C++ 2018.1 adds several new built-in inspections: A new inspection (with a corresponding fix and a code cleanup item) suggests replacingifstatements withif constexprwhen the condition is a compile-time constant expression. Attempted usages of deleted functions are now diagnosed as errors,...
Visual Studio will now use CMake variables from toolchain files to configure IntelliSense. This will provide a better experience for embedded and Android development. Implementation of theMore Constexpr Containers proposal, which allows destructors and new expressions to beconstexpr. This paves the wa...
#include <iostream> #include <regex> #include <string> int main() { try { std::string pattern = "[invalid regex pattern"; std::regex re(pattern); } catch (const std::regex_error& e) { std::cerr << "Regex error: " << e.what() ...
constexpr T&& value() && { if (has_value()) { return std::move(this->m_value); } throw bad_optional_access(); } // you sure are by this point constexpr T const&& value() const&& { if (has_value()) { return std::move(this->m_value); } throw bad_optional_access(); }...