From c8961c7d9fed07190628cf01f9dfad971a942b99 Mon Sep 17 00:00:00 2001 From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com> Date: Mon, 14 Oct 2019 15:46:42 +0300 Subject: doc: Add switch on enum example --- doc/developer-notes.md | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) (limited to 'doc/developer-notes.md') diff --git a/doc/developer-notes.md b/doc/developer-notes.md index f4a5e2d330..9cf4b4b075 100644 --- a/doc/developer-notes.md +++ b/doc/developer-notes.md @@ -87,7 +87,6 @@ code. - `++i` is preferred over `i++`. - `nullptr` is preferred over `NULL` or `(void*)0`. - `static_assert` is preferred over `assert` where possible. Generally; compile-time checking is preferred over run-time checking. - - `enum class` is preferred over `enum` where possible. Scoped enumerations avoid two potential pitfalls/problems with traditional C++ enumerations: implicit conversions to int, and name clashes due to enumerators being exported to the surrounding scope. Block style example: ```c++ @@ -563,6 +562,34 @@ class A - *Rationale*: Easier to understand what is happening, thus easier to spot mistakes, even for those that are not language lawyers. +- Prefer `enum class` (scoped enumerations) over `enum` (traditional enumerations) where possible. + + - *Rationale*: Scoped enumerations avoid two potential pitfalls/problems with traditional C++ enumerations: implicit conversions to `int`, and name clashes due to enumerators being exported to the surrounding scope. + +- `switch` statement on an enumeration example: + +```cpp +enum class Tabs { + INFO, + CONSOLE, + GRAPH, + PEERS +}; + +int GetInt(Tabs tab) +{ + switch (tab) { + case Tabs::INFO: return 0; + case Tabs::CONSOLE: return 1; + case Tabs::GRAPH: return 2; + case Tabs::PEERS: return 3; + } // no default case, so the compiler can warn about missing cases + assert(false); +} +``` + +*Rationale*: The comment documents skipping `default:` label, and it complies with `clang-format` rules. The assertion prevents firing of `-Wreturn-type` warning on some compilers. + Strings and formatting ------------------------ -- cgit v1.2.3