Build{Options,Requirements}: Use a common templated struct

A bit less copy-pasta is a small but appreciable win.

Author: Geod24

source/dub/compilers/buildsettings.d

@@ -57,8 +57,8 @@ struct BuildSettings {
 	string[string] postBuildEnvironments;
 	string[string] preRunEnvironments;
 	string[string] postRunEnvironments;
-	@byName BuildRequirements requirements;
-	@byName BuildOptions options;
+	@byName Flags!BuildRequirement requirements;
+	@byName Flags!BuildOption options;
 
 	BuildSettings dup()
 	const {
@@ -153,11 +153,11 @@ struct BuildSettings {
 	void addPostRunEnvironments(in string[string] value) { add(postRunEnvironments, value); }
 	void updatePostRunEnvironments(in string[string] value) { update(postRunEnvironments, value); }
 	void addRequirements(in BuildRequirement[] value...) { foreach (v; value) this.requirements |= v; }
-	void addRequirements(in BuildRequirements value) { this.requirements |= value; }
+	void addRequirements(in Flags!BuildRequirement value) { this.requirements |= value; }
 	void addOptions(in BuildOption[] value...) { foreach (v; value) this.options |= v; }
-	void addOptions(in BuildOptions value) { this.options |= value; }
+	void addOptions(in Flags!BuildOption value) { this.options |= value; }
 	void removeOptions(in BuildOption[] value...) { foreach (v; value) this.options &= ~v; }
-	void removeOptions(in BuildOptions value) { this.options &= ~value; }
+	void removeOptions(in Flags!BuildOption value) { this.options &= ~value; }
 
 private:
 	static auto filterDuplicates(T)(ref string[] arr, in T vals, bool noDuplicates = true)
@@ -342,15 +342,6 @@ enum BuildRequirement {
 	noDefaultFlags       = 1<<9,  /// Do not issue any of the default build flags (e.g. -debug, -w, -property etc.) - use only for development purposes
 }
 
-	struct BuildRequirements {
-		import dub.internal.vibecompat.data.serialization : ignore;
-
-		@ignore BitFlags!BuildRequirement values;
-		this(BuildRequirement req) { values = req; }
-
-		alias values this;
-	}
-
 enum BuildOption {
 	none = 0,                     /// Use compiler defaults
 	debugMode = 1<<0,             /// Compile in debug mode (enables contracts, -debug)
@@ -385,16 +376,24 @@ enum BuildOption {
 	_ddox = 1<<27,                // Compile docs.json
 }
 
-	struct BuildOptions {
-		import dub.internal.vibecompat.data.serialization : ignore;
+struct Flags (T) {
+	import dub.internal.vibecompat.data.serialization : ignore;
+
+	@ignore BitFlags!T values;
 
-		@ignore BitFlags!BuildOption values;
-		this(BuildOption opt) { values = opt; }
-		this(BitFlags!BuildOption v) { values = v; }
+	public this(T opt) @safe pure nothrow @nogc
+	{
+		this.values = opt;
+	}
 
-		alias values this;
+	public this(BitFlags!T v) @safe pure nothrow @nogc
+	{
+		this.values = v;
 	}
 
+	alias values this;
+}
+
 /**
 	All build options that will be inherited upwards in the dependency graph
 
@@ -405,11 +404,18 @@ enum BuildOption {
 		$(LI The option enabled meta information in dependent projects that are useful for the dependee (e.g. debug information))
 	)
 */
-enum BuildOptions inheritedBuildOptions = BuildOption.debugMode | BuildOption.releaseMode
+enum Flags!BuildOption inheritedBuildOptions =
+	BuildOption.debugMode | BuildOption.releaseMode
 	| BuildOption.coverage | BuildOption.coverageCTFE | BuildOption.debugInfo | BuildOption.debugInfoC
 	| BuildOption.alwaysStackFrame | BuildOption.stackStomping | BuildOption.inline
 	| BuildOption.noBoundsCheck | BuildOption.profile | BuildOption.ignoreUnknownPragmas
 	| BuildOption.syntaxOnly | BuildOption.warnings	| BuildOption.warningsAsErrors
 	| BuildOption.ignoreDeprecations | BuildOption.deprecationWarnings
 	| BuildOption.deprecationErrors | BuildOption.property | BuildOption.profileGC
 	| BuildOption.pic;
+
+deprecated("Use `Flags!BuildOption` instead")
+public alias BuildOptions = Flags!BuildOption;
+
+deprecated("Use `Flags!BuildRequirement` instead")
+public alias BuildRequirements = Flags!BuildRequirement;

source/dub/compilers/utils.d

@@ -187,11 +187,11 @@ void resolveLibs(ref BuildSettings settings, const scope ref BuildPlatform platf
 	equivalent.
 
 	Certain compiler flags should, instead of using compiler-specific syntax,
-	be specified as build options (`BuildOptions`) or built requirements
+	be specified as build options (`BuildOption`) or built requirements
 	(`BuildRequirements`). This function will output warning messages to
 	assist the user in making the best choice.
 */
-void warnOnSpecialCompilerFlags(string[] compiler_flags, BuildOptions options, string package_name, string config_name)
+void warnOnSpecialCompilerFlags(string[] compiler_flags, Flags!BuildOption options, string package_name, string config_name)
 {
 	import std.algorithm : any, endsWith, startsWith;
 	import std.range : empty;

source/dub/generators/generator.d

@@ -720,7 +720,7 @@ class ProjectGenerator
 	{
 		child.addVersions(parent.versions);
 		child.addDebugVersions(parent.debugVersions);
-		child.addOptions(BuildOptions(parent.options & inheritedBuildOptions));
+		child.addOptions(Flags!BuildOption(parent.options & inheritedBuildOptions));
 	}
 
 	private static void mergeFromDependency(const scope ref BuildSettings child, ref BuildSettings parent, const scope ref BuildPlatform platform)

source/dub/project.d

@@ -1054,9 +1054,9 @@ shared static this() {
 				return value.byKeyValue.map!(a => a.key ~ "=" ~ a.value);
 			else static if( is(typeof(value) == enum) )
 				return only(value);
-			else static if( is(typeof(value) == BuildRequirements) )
+			else static if( is(typeof(value) == Flags!BuildRequirement) )
 				return only(cast(BuildRequirement) cast(int) value.values);
-			else static if( is(typeof(value) == BuildOptions) )
+			else static if( is(typeof(value) == Flags!BuildOption) )
 				return only(cast(BuildOption) cast(int) value.values);
 			else
 				static assert(false, "Type of BuildSettings."~attributeName~" is unsupported.");

source/dub/recipe/json.d

@@ -246,13 +246,13 @@ private void parseJson(ref BuildSettingsTemplate bs, Json json, string package_n
 			case "preRunEnvironments": bs.preRunEnvironments[suffix] = deserializeJson!(string[string])(value); break;
 			case "postRunEnvironments": bs.postRunEnvironments[suffix] = deserializeJson!(string[string])(value); break;
 			case "buildRequirements":
-				BuildRequirements reqs;
+				Flags!BuildRequirement reqs;
 				foreach (req; deserializeJson!(string[])(value))
 					reqs |= to!BuildRequirement(req);
 				bs.buildRequirements[suffix] = reqs;
 				break;
 			case "buildOptions":
-				BuildOptions options;
+				Flags!BuildOption options;
 				foreach (opt; deserializeJson!(string[])(value))
 					options |= to!BuildOption(opt);
 				bs.buildOptions[suffix] = options;

source/dub/recipe/packagerecipe.d

@@ -214,8 +214,8 @@ struct BuildSettingsTemplate {
 	string[string][string] postBuildEnvironments;
 	string[string][string] preRunEnvironments;
 	string[string][string] postRunEnvironments;
-	BuildRequirements[string] buildRequirements;
-	BuildOptions[string] buildOptions;
+	Flags!BuildRequirement[string] buildRequirements;
+	Flags!BuildOption[string] buildOptions;
 
 
 	/// Constructs a BuildSettings object from this template.
@@ -354,7 +354,7 @@ struct BuildSettingsTemplate {
 			logWarn("");
 		} else {
 			string[] all_dflags;
-			BuildOptions all_options;
+			Flags!BuildOption all_options;
 			foreach (flags; this.dflags) all_dflags ~= flags;
 			foreach (options; this.buildOptions) all_options |= options;
 			.warnOnSpecialCompilerFlags(all_dflags, all_options, package_name, config_name);