Class with private constructor and static array of itself
c++,c++11,initialization,static-initialization,stdarray
The solution: std::array<SomeThing, 64> SomeThing::lookup_table_0 {{ }}; Note: as explained here, {{}} is required to value-initialize the std::array without warnings in gcc. = {} and {} are correct but gcc warns anyway. The key to the solution is that some form of initializer must be present. A terminology check first:...
How can one accomplish this static initialization in ANSI C? Macro?
c,static,static-initialization
You can write as follows in C99. sample #include <stdio.h> #include <stdlib.h> #include <stdint.h> typedef struct ex { uint16_t m1; int m2; char *m3; } Type; int main(void){ Type *p = calloc(1, sizeof(Type)); *p = (Type){ .m1 = 4 | 2, .m3 = "string" //can't put ';' }; printf("m1:%hu\nm2:%d\nm3:%s\n", p->m1,...
Are there circumstances under which Java does not initialize static fields immediately?
Static variables are instantiated by the JVM classloader and are shared by every instance of the class. public class StaticVars { static int i = 3; public static void main( String[] args ) { System.out.println( "Called at Runtime: " + getStaticVar() ); System.out.println( "Called via it's static member: " +...
Fortran derived type in common: initialization?
fortran,fortran90,static-initialization
From the line integer :: acc = -1 strip off the trailing = -1 to leave integer :: acc recompile, and see what happens. The error message suggests that a program can't initialise a derived type component and use variables of that derived type in common statements. 'Initialize' is used...
Java: use static initializer blocks to register classes to global static registry
I read that the static initializers are executed when the class is first loaded and since I do not reference those classes anywhere in code directly, they are not loaded and the static initializers are not executed. This is correct -- unless you access the class somewhere, none of...
Initializing a static std::map> in C++
c++,templates,inheritance,static-initialization
This is one possible implementation: template <typename T, typename U> class create_map { private: std::map<T, U> m_map; public: create_map(T key, U val) { m_map.emplace(std::move(key), std::move(val)); } create_map&& operator()(T key, U val) && { m_map.emplace(std::move(key), std::move(val)); return std::move(*this); } operator std::map<T, U>() && { return std::move(m_map); } }; Note the taking...