build: Bump C++ to C++17

Now requires gcc8 or clang7

.clang-format

@@ -1,6 +1,6 @@
 ---
 Language: Cpp
-Standard: Cpp11
+Standard: c++17
 BasedOnStyle: Google
 ColumnLimit: 120
 NamespaceIndentation: All

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Build
 - Respect `CMAKE_INSTALL_PREFIX` when installing default config ([`#2770`](https://github.com/polybar/polybar/pull/2770))
+- Bump C++ version to C++17 ([`#2847`](https://github.com/polybar/polybar/pull/2847))
 
 ### Deprecated
 - `custom/text`: The `content` setting and all its properties are deprecated in favor of `format` with the same functionality. ([`#2676`](https://github.com/polybar/polybar/pull/2676))

cmake/cxx.cmake

@@ -15,13 +15,12 @@ endif()
 option(CXXLIB_CLANG "Link against libc++" OFF)
 option(CXXLIB_GCC "Link against stdlibc++" OFF)
 
-set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 
-
 set(POLYBAR_FLAGS "" CACHE STRING "C++ compiler flags used for compiling polybar")
 
 list(APPEND cxx_base -Wall -Wextra -Wpedantic -Wdeprecated-copy-dtor)