Add C++ formatting pre-commit hook (#247)

Author: antepusic

Diff for: .githooks/pre-commit

@@ -0,0 +1,33 @@
+#!/bin/sh
+
+project_folder=$(git rev-parse --show-toplevel)
+if git rev-parse --verify HEAD >/dev/null 2>&1; then
+  against=HEAD
+else
+  # Initial commit: diff against an empty tree object
+  against=$(git hash-object -t tree /dev/null)
+fi
+
+# Redirect output to stderr.
+exec 1>&2
+
+tmpdir=$(mktemp -d repo-XXXXXXXX)
+trap "rm -rf $tmpdir" EXIT INT
+
+modified_files=$(git diff --cached --name-only --diff-filter=AM $against | sed -nE "/.*\.(cpp|cc|cxx|c|h|hpp)$/p")
+FAIL=0
+
+for file in $modified_files; do
+  echo "Checking $file..."
+
+  cp $project_folder/cpp/.clang-format $project_folder/cpp/.clang-tidy $tmpdir
+
+  git checkout-index --prefix="$tmpdir/" -- $file
+
+  CODE=$?
+  if [ $CODE -ne 0 ]; then
+    FAIL=1
+  fi
+done
+
+return ${FAIL}

Diff for: cpp/.clang-format

@@ -1,9 +1,9 @@
 ---
-Language:     Cpp
+Language: Cpp
 BasedOnStyle: Google
-Standard:     "c++17"
-UseTab:       Never
+Standard: "c++20"
+UseTab: Never
 DerivePointerAlignment: false
 PointerAlignment: Right
-ColumnLimit : 120
-IncludeBlocks: Preserve
+ColumnLimit: 120
+IncludeBlocks: Preserve

Diff for: cpp/.clang-tidy

@@ -0,0 +1,91 @@
+---
+Checks: "*,
+  -abseil-string-find-str-contains,
+  -altera-id-dependent-backward-branch,
+  -altera-struct-pack-align,
+  -altera-unroll-loops,
+  -android-*,
+  -cert-err58-cpp,
+  -cppcoreguidelines-avoid-c-arrays,
+  -cppcoreguidelines-avoid-goto,
+  -cppcoreguidelines-avoid-magic-numbers,
+  -cppcoreguidelines-no-malloc,
+  -cppcoreguidelines-non-private-member-variables-in-classes,
+  -cppcoreguidelines-owning-memory,
+  -cppcoreguidelines-pro-bounds-array-to-pointer-decay,
+  -cppcoreguidelines-pro-bounds-constant-array-index,
+  -cppcoreguidelines-pro-bounds-pointer-arithmetic,
+  -cppcoreguidelines-pro-type-member-init,
+  -cppcoreguidelines-pro-type-reinterpret-cast,
+  -cppcoreguidelines-pro-type-static-cast-downcast,
+  -cppcoreguidelines-pro-type-union-access,
+  -cppcoreguidelines-pro-type-vararg,
+  -cppcoreguidelines-special-member-functions,
+  -fuchsia-default-arguments,
+  -fuchsia-default-arguments-calls,
+  -fuchsia-default-arguments-declarations,
+  -fuchsia-overloaded-operator,
+  -fuchsia-statically-constructed-objects,
+  -fuchsia-trailing-return,
+  -fuchsia-virtual-inheritance,
+  -google-explicit-constructor,
+  -google-readability-*,
+  -google-runtime-references,
+  -hicpp-avoid-c-arrays,
+  -hicpp-avoid-goto,
+  -hicpp-braces-around-statements,
+  -hicpp-member-init,
+  -hicpp-no-array-decay,
+  -hicpp-no-assembler,
+  -hicpp-no-malloc,
+  -hicpp-use-equals-default,
+  -hicpp-use-nullptr,
+  -hicpp-vararg,
+  -llvm-header-guard,
+  -llvm-include-order,
+  -llvmlibc-callee-namespace,
+  -llvmlibc-implementation-in-namespace,
+  -llvmlibc-restrict-system-libc-headers,
+  -misc-non-private-member-variables-in-classes,
+  -modernize-avoid-c-arrays,
+  -modernize-concat-nested-namespaces,
+  -modernize-pass-by-value,
+  -modernize-use-equals-default,
+  -modernize-use-nodiscard,
+  -modernize-use-trailing-return-type,
+  -performance-unnecessary-value-param,
+  -readability-braces-around-statements,
+  -readability-else-after-return,
+  -readability-function-cognitive-complexity,
+  -readability-implicit-bool-conversion,
+  -readability-magic-numbers,
+  -readability-named-parameter,
+  -misc-no-recursion,
+  -concurrency-mt-unsafe,
+  -bugprone-easily-swappable-parameters"
+
+WarningsAsErrors: ""
+HeaderFilterRegex: "src/.*"
+AnalyzeTemporaryDtors: false
+FormatStyle: none
+CheckOptions:
+  - key: google-readability-braces-around-statements.ShortStatementLines
+    value: "1"
+  - key: google-readability-function-size.StatementThreshold
+    value: "800"
+  - key: google-readability-namespace-comments.ShortNamespaceLines
+    value: "10"
+  - key: google-readability-namespace-comments.SpacesBeforeComments
+    value: "2"
+  - key: modernize-loop-convert.MaxCopySize
+    value: "16"
+  - key: modernize-loop-convert.MinConfidence
+    value: reasonable
+  - key: modernize-loop-convert.NamingStyle
+    value: CamelCase
+  - key: modernize-pass-by-value.IncludeStyle
+    value: llvm
+  - key: modernize-replace-auto-ptr.IncludeStyle
+    value: llvm
+  - key: modernize-use-nullptr.NullMacros
+    value: "NULL"