Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, folder names, filenames, file extensions, pathnames, user input and program output.

Here is an example: “Then you create a union type with std::variant, saying that this union type may be and can only be from the pre-defined Lua mappings.”

A block of code is set as follows:

void LuaExecutor::setRegistry(const LuaValue &key,
                              const LuaValue &value)
{
    pushValue(key);
    pushValue(value);
    lua_settable(L, LUA_REGISTRYINDEX);
}

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

int luaNew(lua_State *L)
{
    ....
    if (type == LUA_TNIL)
    {
        ...
        lua_pushcfunction(L, luaDelete);
        lua_setfield(L, -2, "__gc");
    }
    ...
}

Bold: Indicates a new term, an important concept, or crucial software. Here is an example: “All systems with graphic user interfaces will also provide an application in which to start a shell. Often, those applications are called a terminal or a console.”

Tips or important notes

Appear like this.