feat: Use clang-format to lint C++ code

.clang-format

@@ -0,0 +1,26 @@
+# Config for clang-format version 16
+
+# Standard
+BasedOnStyle: llvm
+Standard: c++14
+
+# Indentation
+IndentWidth: 2
+ColumnLimit: 100
+
+# Includes
+SortIncludes: true
+SortUsingDeclarations: true
+
+# Pointer and reference alignment
+PointerAlignment: Left
+ReferenceAlignment: Left
+ReflowComments: true
+
+# Line breaking options
+BreakBeforeBraces: Attach
+BreakConstructorInitializers: BeforeColon
+AllowShortFunctionsOnASingleLine: Empty
+IndentCaseLabels: true
+NamespaceIndentation: Inner
+

.github/actions/setup/validate-cpp.yml

@@ -0,0 +1,36 @@
+name: Validate C++
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - '.github/workflows/validate-cpp.yml'
+      - 'cpp/**'
+      - 'android/src/main/cpp/**'
+      - 'ios/**'
+  pull_request:
+    paths:
+      - '.github/workflows/validate-cpp.yml'
+      - 'cpp/**'
+      - 'android/src/main/cpp/**'
+      - 'ios/**'
+
+jobs:
+  lint:
+    name: Check clang-format
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        path:
+          - 'cpp'
+          - 'android/src/main/cpp'
+          - 'ios'
+    steps:
+      - uses: actions/checkout@v2
+      - name: Run clang-format style check
+        uses: jidicula/clang-format-action@v4.11.0
+        with:
+          clang-format-version: '16'
+          check-path: ${{ matrix.path }}
+

scripts/clang-format.sh

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+if which clang-format >/dev/null; then
+  find cpp ios android/src/main/cpp -type f \( -name "*.h" -o -name "*.cpp" -o -name "*.m" -o -name "*.mm" \) -print0 | while read -d $'\0' file; do
+    echo "-> cpp-lint $file"
+    clang-format -i "$file"
+  done
+else
+  echo "warning: clang-format not installed, download from https://clang.llvm.org/docs/ClangFormat.html (or run brew install clang-format)"
+fi