C/C++: improve extra fontification; add modern-cpp-font-lock plugin

Cask

@@ -150,6 +150,7 @@
 (depends-on "irony")
 (depends-on "irony-eldoc")
 (depends-on "opencl-mode")
+(depends-on "modern-cpp-font-lock")
 
 ;; Crystal -- modules/module-crystal.el
 (depends-on "crystal-mode" :git "https://github.com/jpellerin/emacs-crystal-mode")

modules/defuns/defuns-cc.el

@@ -72,35 +72,12 @@
   (set new-face new-face))
 
 ;;;###autoload
-(defun doom|init-c++-C11-highlights ()
+(defun doom|extra-fontify-c++ ()
-  ;; C++11 syntax support (until cc-mode is updated)
-  (require 'font-lock)
-  ;; labels, case, public, private, protected, namespace-tags
-  (doom--copy-face 'font-lock-label-face 'font-lock-keyword-face)
-  ;; comment markups such as Javadoc-tags
-  (doom--copy-face 'font-lock-doc-markup-face 'font-lock-doc-face)
-  ;; comment markups
-  (doom--copy-face 'font-lock-doc-string-face 'font-lock-comment-face)
-  (setq font-lock-maximum-decoration t)
-
   ;; We could place some regexes into `c-mode-common-hook', but
   ;; note that their evaluation order matters.
+  ;; NOTE modern-cpp-font-lock will eventually supercede some of these rules
   (font-lock-add-keywords
-   nil '(;; complete some fundamental keywords
+   nil '(;; c++11 string literals
-         ("\\<\\(void\\|unsigned\\|signed\\|char\\|short\\|bool\\|int\\|long\\|float\\|double\\)\\>" . font-lock-keyword-face)
-         ;; namespace names and tags - these are rendered as constants by cc-mode
-         ("\\<\\(\\w+::\\)" . font-lock-function-name-face)
-         ;;  new C++11 keywords
-         ("\\<\\(alignof\\|alignas\\|constexpr\\|decltype\\|noexcept\\|nullptr\\|static_assert\\|thread_local\\|override\\|final\\)\\>" . font-lock-keyword-face)
-         ("\\<\\(char16_t\\|char32_t\\)\\>" . font-lock-keyword-face)
-         ;; PREPROCESSOR_CONSTANT, PREPROCESSORCONSTANT
-         ("\\<[A-Z]*_[A-Z_]+\\>" . font-lock-constant-face)
-         ("\\<[A-Z]\\{3,\\}\\>"  . font-lock-constant-face)
-         ;; hexadecimal numbers
-         ("\\<0[xX][0-9A-Fa-f]+\\>" . font-lock-constant-face)
-         ;; integer/float/scientific numbers
-         ("\\<[\\-+]*[0-9]*\\.?[0-9]+\\([ulUL]+\\|[eE][\\-+]?[0-9]+\\)?\\>" . font-lock-constant-face)
-         ;; c++11 string literals
          ;;       L"wide string"
          ;;       L"wide string with UNICODE codepoint: \u2018"
          ;;       u8"UTF-8 string", u"UTF-16 string", U"UTF-32 string"
@@ -112,10 +89,23 @@
          ("\\(\\<[uU8]*R\"[^\\s-\\\\()]\\{0,16\\}(\\)" 1 font-lock-keyword-face t) ; start delimiter
          (   "\\<[uU8]*R\"[^\\s-\\\\()]\\{0,16\\}(\\(.*?\\))[^\\s-\\\\()]\\{0,16\\}\"" 1 font-lock-string-face t)  ; actual string
          (   "\\<[uU8]*R\"[^\\s-\\\\()]\\{0,16\\}(.*?\\()[^\\s-\\\\()]\\{0,16\\}\"\\)" 1 font-lock-keyword-face t) ; end delimiter
+         ) t))
 
-         ;; user-defined types (rather project-specific)
+;;;###autoload
-         ("\\<[A-Za-z_]+[A-Za-z_0-9]*_\\(type\\|ptr\\)\\>" . font-lock-type-face)
+(defun doom|extra-fontify-c/c++ ()
-         ("\\<\\(xstring\\|xchar\\)\\>" . font-lock-type-face)
+  (font-lock-add-keywords
+   nil '(;; PREPROCESSOR_CONSTANT, PREPROCESSORCONSTANT
+         ("\\<[A-Z]*_[A-Z_]+\\>" . font-lock-constant-face)
+         ("\\<[A-Z]\\{3,\\}\\>"  . font-lock-constant-face)
+         ;; integer/float/scientific numbers
+         ("\\<\\([\\-+]*[0-9\\.]+\\)\\>" 1 font-lock-constant-face t)
+         ("\\<\\([\\-+]*[0-9\\.]+\\)\\(f\\)\\>"
+          (1 font-lock-constant-face t)
+          (2 font-lock-keyword-face t))
+         ("\\<\\([\\-+]*[0-9\\.]+\\)\\([eE]\\)\\([\\-+]?[0-9]+\\)\\>"
+          (1 font-lock-constant-face t)
+          (2 font-lock-keyword-face t)
+          (3 font-lock-constant-face t))
          ) t))
 
 ;;;###autoload

modules/module-cc.el

@@ -4,7 +4,9 @@
   :commands (c-mode c++-mode objc-mode java-mode)
   :mode ("\\.mm" . objc-mode)
   :init
-  (add-hook! c++-mode '(highlight-numbers-mode doom|init-c++-C11-highlights))
+  (add-hook! (c-mode c++-mode) 'doom|extra-fontify-c/c++)
+  (add-hook 'c-mode-hook 'highlight-numbers-mode)
+  (add-hook 'c++-mode-hook 'doom|extra-fontify-c++)
   (add-hook 'c-initialization-hook 'doom|init-c/c++-settings)
 
   ;; C++ header files
@@ -40,6 +42,10 @@
   ;; Improve indentation of inline lambdas in C++11
   (advice-add 'c-lineup-arglist :around 'doom/c-lineup-arglist))
 
+(use-package modern-cpp-font-lock
+  :commands modern-c++-font-lock-mode
+  :init (add-hook 'c++-mode-hook 'modern-c++-font-lock-mode))
+
 (use-package irony
   :after cc-mode
   :config