Calling Functions A Tutorial Klaus Iglberger, CppCon 2020 klaus.iglberger@gmx.de2 Klaus Iglberger C++ Trainer since 2016 Author of the C++ math library (Co-)Organizer of the Munich Dispatch Deleting FunctionsDisclaimer 5 This talk does … … focus on the basic mechanics of calling functions; … point out the surprising details; … give further references whenever necessary.

with requires expression Concept (named requirements) // OK, uses 1st add() calling push_back() // OK, uses 2nd add() calling insert() Nico Josuttis C++ Concepts @cppcon 2024-09-18 3©2024 by josuttis coll1; std::set coll2; add(coll1, 42); // OK, uses 1st add() calling push_back() add(coll2, 42); // OK, uses 2nd add() calling insert() C++20 C++20 Type Constraints with concepts applied to types add(coll1, 42); add(coll2, 42); // C++20 C++20 // ERROR: "can't call insert()" // OK, uses 2nd add() calling insert() 2nd add() is used, because concept for 1st add() not satisfied Requirements not met =>

6 $BITPACKING : Enable bitsize packing . . . . . . . . . . . . . . . . . . . 17 1.2.7 $CALLING : Specify calling convention . . . . . . . . . . . . . . . . . . . . 17 1.2.8 $CHECKPOINTER : Check pointer smartlinking . . . . . . . . . . . . . . . . . . . . . . . 53 1.3.34 $SYSCALLS : Select system calling convention on Amiga/MorphOS . . . . 54 1.3.35 $THREADNAME : Set thread name in Netware . . . . 83 6.2.3 Modifying the mangled names . . . . . . . . . . . . . . . . . . . . . . . . . 85 6.3 Calling mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 6.4 Nested procedure

not a tab. The second important part is println!. This is calling a Rust macro, which is how metaprogramming is done in Rust. If it were calling a function instead, it would look like this: println (without detail in Appendix E, but for now you just need to know that when you see a ! that means that you’re calling a macro instead of a normal function. Next is “Hello, world!” which is a string. We pass this string the other side of the equal sign (=) is the value that guess is bound to, which is the result of calling String::new, a func- tion that returns a new instance of a String. String is a string type provided

Declarations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 8.4.1 Calling Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 8.4.2 Foreign foreign code that follows the C calling convention. However, the design of the FFI is such that it enables the modular extension of the present definition to include the calling conventions of other programming guaranteed to match the representation of int. The specification of external names, dependent on a calling convention, is described in Section 8.5, whereas the marshalling of the basic types in dependence

Cmd Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342 27 Calling C and Fortran Code 344 27.1 Creating C-Compatible Julia Function Pointers . . . . . . . . . . . ccall interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 27.13 Calling Convention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 27.14 Accessing Converting Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 30.4 Calling Julia Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381 30.5 Memory

Cmd Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342 27 Calling C and Fortran Code 344 27.1 Creating C-Compatible Julia Function Pointers . . . . . . . . . . . ccall interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 27.13 Calling Convention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 27.14 Accessing Converting Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 30.4 Calling Julia Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381 30.5 Memory

The code page of a string can be set explicitly using the SetCodePage routine of the system unit. Calling this routine will convert the value of a string to the requested code page. Remark Code page conversions -MTP switches are used, the address operator can be dropped. Remark The modifiers concerning the calling conventions must be the same as the declaration; i. e. the following code would give an error: 57 end; begin Proc := @printit; end. Because the TOneArgCcall type is a procedure that uses the cdecl calling convention. In case the is nested modified is added, then the procedural variable can be used with

by another program or the operating system and both sides of the interface have to agree on the calling convention and, in most cases, use the same programming language, web services use Internet standards COM/XPCOM variant of the Main API, a client that wants to use the web service must first log on by calling the IWebsessionManager::logon() API (see chapter 9.49.3, logon, page 222) that is specific to the create such an object, but vboxwebsrv creates one for you when you log on, which you can obtain by calling IWebsessionManager::getSessionObject(). This session object must then be used like a mutex semaphore

Cmd Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 28 Calling C and Fortran Code 365 28.1 Creating C-Compatible Julia Function Pointers . . . . . . . . . . . ccall interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382 28.13 Calling Convention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 28.14 Accessing Converting Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403 31.4 Calling Julia Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404 31.5 Memory