Язык Go для С++ программистов

Go For C++ Programmers

Go is a systems programming language intended to be a general-purpose systems language, like C++. These are some notes on Go for experienced C++ programmers. This document discusses the differences between Go and C++, and says little to nothing about the similarities.

For a more general introduction to Go, see the Go tutorial and Effective Go.

For a detailed description of the Go language, see the Go spec.

Conceptual Differences

Go does not have classes with constructors or destructors. Instead of class methods, a class inheritance hierarchy, and virtual functions, Go provides interfaces, which arediscussed in more detail below. Interfaces are also used where C++ uses templates.

Go uses garbage collection. It is not necessary (or possible) to release memory explicitly. The garbage collection is (intended to be) incremental and highly efficient on modern processors.

Go has pointers but not pointer arithmetic. You cannot use a pointer variable to walk through the bytes of a string.

Arrays in Go are first class values. When an array is used as a function parameter, the function receives a copy of the array, not a pointer to it. However, in practice functions often use slices for parameters; slices hold pointers to underlying arrays. Slices are discussed further below.

Strings are provided by the language. They may not be changed once they have been created.

Hash tables are provided by the language. They are called maps.

Separate threads of execution, and communication channels between them, are provided by the language. This is discussed further below.

Certain types (maps and channels, described further below) are passed by reference, not by value. That is, passing a map to a function does not copy the map, and if the function changes the map the change will be seen by the caller. In C++ terms, one can think of these as being reference types.

Go does not use header files. Instead, each source file is part of a defined package. When a package defines an object (type, constant, variable, function) with a name starting with an upper case letter, that object is visible to any other file which imports that package.