1. Keywords

2. Outline In this lesson, we will: Review keywords
Look at the list of all keywords
Consider issues of using keywords as identifiers
Review reserved identifiers

3. Keywords
We have seen these identifiers that are reserved by the C++ programming language:
return throw
if else while for do break
void signed unsigned
bool true false
char short int long
float double
struct const
goto

4. Keywords These are also common English-language keywords:
and auto case catch
class concept continue default
delete explicit export friend
import module mutable new
not operator or private
protected public register requires
static switch synchronized template
this try typedef union
using virtual volatile

5. Keywords Other keywords are acronyms or abbreviations
alignas alignof and_eq asm
atomic_cancel atomic_commit atomic_noexcept bitand
bitor char16_t char32_t compl
constexpr const_cast co_await co_return
co_yield decltype dynamic_cast enum
extern inline namespace noexcept
not_eq nullptr or_eq reinterpret_cast
sizeof static_assert static_cast thread_local
typeid typename wchar_t xor
xor_eq

6. Keywords Most programming languages have keywords
The C++ programming language has approximately 100 keywords
The C programming language has only 32
Issue: because keywords are part of the language, the errors will appear very bizarre
A unknown identifier has a straight-forward error message
A keyword will see the compiler trying to understand the context in which that keyword should be used in

7. Reserved identifiers A gentle reminder
Reserved identifiers are for the use of the compiler, the standard libraries, etc.
Any identifier starting with an underscore or containing to adjacent underscores is a reserved identifier
If you use such a reserved identifier, your code may work, but it may also fail with the next update to the standard library, your compiler, etc.

8. Summary Following this lesson, you now:
Have been exposed to all keywords in C++
Know that you don’t have to memorize these
Know that accidental use will result in significantly different error messages

9. References
[1] No references?

10. Colophon
These slides were prepared using the Georgia typeface. Mathematical equations use Times New Roman, and source code is presented using Consolas. The photographs of lilacs in bloom appearing on the title slide and accenting the top of each other slide were taken at the Royal Botanical Gardens on May 27, 2018 by Douglas Wilhelm Harder. Please see for more information.

11. Disclaimer
These slides are provided for the ece 150 Fundamentals of Programming course taught at the University of Waterloo. The material in it reflects the authors’ best judgment in light of the information available to them at the time of preparation. Any reliance on these course slides by any party for any other purpose are the responsibility of such parties. The authors accept no responsibility for damages, if any, suffered by any party as a result of decisions made or actions based on these course slides for any other purpose than that for which it was intended.