diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000..bd04385
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,131 @@
+# -*- mode: yaml -*-
+# Written for clang-format 11.
+# https://releases.llvm.org/11.0.0/tools/clang/docs/ClangFormatStyleOptions.html
+---
+DisableFormat: false
+Language: Cpp
+
+AccessModifierOffset: -4
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: false
+AlignConsecutiveBitFields: false
+AlignConsecutiveDeclarations: false
+AlignConsecutiveMacros: false
+AlignEscapedNewlines: DontAlign
+AlignOperands: Align
+AlignTrailingComments: true
+AllowAllArgumentsOnNextLine: false
+AllowAllConstructorInitializersOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+AllowShortBlocksOnASingleLine: Empty
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortEnumsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: Empty
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLambdasOnASingleLine: Inline
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: Yes
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:                  # If BreakBeforeBraces is set to Custom.
+  AfterCaseLabel: true
+  AfterClass: true
+  AfterControlStatement: Always
+  AfterEnum: true
+  AfterFunction: true
+  AfterNamespace: true
+  AfterStruct: true
+  AfterUnion: true
+  AfterExternBlock: true
+  BeforeCatch: true
+  BeforeElse: true
+  BeforeLambdaBody: true
+  BeforeWhile: true
+  IndentBraces: false
+  SplitEmptyFunction: false
+  SplitEmptyRecord: false
+  SplitEmptyNamespace: false
+BreakBeforeBinaryOperators: NonAssignment
+BreakBeforeBraces: Custom
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: BeforeComma
+BreakInheritanceList: BeforeComma
+BreakStringLiterals: true
+ColumnLimit: 80
+# CommentPragmas: 'regex'
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DeriveLineEnding: true
+DerivePointerAlignment: false
+FixNamespaceComments: true
+ForEachMacros:
+  - FOREACH
+  - RANGES_FOR
+  - Q_FOREACH
+  - BOOST_FOREACH
+IncludeBlocks: Regroup
+IncludeCategories:              # stdlib headers into own group.
+  - Regex: '^[^\.]+$'
+    Priority: 4
+IndentCaseBlocks: false
+IndentCaseLabels: false
+IndentExternBlock: NoIndent
+IndentGotoLabels: false
+IndentPPDirectives: AfterHash
+IndentWidth: 4
+IndentWrappedFunctionNames: false
+KeepEmptyLinesAtTheStartOfBlocks: true
+# MacroBlockBegin: 'string'
+# MacroBlockEnd:   'string'
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+# NamespaceMacros: 'string'
+PenaltyBreakAssignment: 250
+PenaltyBreakBeforeFirstCallParameter: 300
+# PenaltyBreakComment: 300
+# PenaltyBreakFirstLessLess: 120
+# PenaltyBreakString: 1000
+# PenaltyBreakTemplateDeclaration: 10
+# PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 100
+PointerAlignment: Right
+# RawStringFormats: # <YAML>
+ReflowComments: true
+SortIncludes: true
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceBeforeSquareBrackets: false
+SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles: false
+SpacesInCStyleCastParentheses: false
+SpacesInConditionalStatement: false
+SpacesInContainerLiterals: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard: Auto
+# StatementMacros:
+#   - Q_UNUSED
+#   - QT_REQUIRE_VERSION
+TabWidth: 4
+# TypenameMacros:
+#   - STACK_OF
+#   - LIST
+UseCRLF: false
+UseTab: Never
+# WhitespaceSensitiveMacros: ['string', 'string']
+...
diff --git a/.clang-tidy b/.clang-tidy
new file mode 100644
index 0000000..fc14d6c
--- /dev/null
+++ b/.clang-tidy
@@ -0,0 +1,47 @@
+# -*- mode: conf; fill-column: 100; -*-
+# Written for clang-tidy 11.
+
+---
+Checks:         '*,
+                -cppcoreguidelines-non-private-member-variables-in-classes,
+                -fuchsia-default-arguments-calls,
+                -fuchsia-default-arguments-declarations,
+                -fuchsia-default-arguments,
+                -llvm-include-order,
+                -llvm-header-guard,
+                -misc-non-private-member-variables-in-classes,
+                -fuchsia-overloaded-operator,
+                -cppcoreguidelines-avoid-magic-numbers,
+                -readability-magic-numbers,
+                -cppcoreguidelines-pro-bounds-array-to-pointer-decay,
+                -hicpp-no-array-decay,
+                -modernize-avoid-c-arrays,
+                -cppcoreguidelines-avoid-c-arrays,
+                -hicpp-avoid-c-arrays,
+                -google-build-using-namespace,
+                -readability-named-parameter,
+                -google-runtime-references,
+                -hicpp-avoid-goto,
+                -hicpp-vararg,
+                -fuchsia-statically-constructed-objects,
+                -google-readability-todo,
+                -modernize-use-trailing-return-type,
+                -fuchsia-multiple-inheritance,
+                -llvmlibc*,
+                -cppcoreguidelines-avoid-non-const-global-variables,
+                -cert-*-c'
+FormatStyle:    file            # Use .clang-format.
+CheckOptions:   # ↓ Clashes with static private member prefix. (static int _var;) ↓
+                - { key: readability-identifier-naming.VariableCase,          value: lower_case }
+                - { key: readability-identifier-naming.MemberCase,            value: lower_case }
+                - { key: readability-identifier-naming.PrivateMemberCase,     value: lower_case }
+                - { key: readability-identifier-naming.PrivateMemberPrefix,   value: _          }
+                - { key: readability-identifier-naming.ProtectedMemberCase,   value: lower_case }
+                - { key: readability-identifier-naming.ProtectedMemberPrefix, value: _          }
+
+                - { key: readability-identifier-naming.ClassCase,             value: lower_case  }
+                - { key: readability-identifier-naming.StructCase,            value: lower_case }
+                - { key: readability-identifier-naming.EnumCase,              value: lower_case }
+                - { key: readability-identifier-naming.FunctionCase,          value: lower_case }
+                - { key: readability-identifier-naming.ParameterCase,         value: lower_case }
+...