C++17 build for macos

Author: rsjaffe

build/MacOS/MIDI2LR.xcodeproj/project.pbxproj

@@ -470,7 +470,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ARCHS = "$(ARCHS_STANDARD_64_BIT)";
-				CLANG_CXX_LANGUAGE_STANDARD = "c++20";
+				CLANG_CXX_LANGUAGE_STANDARD = "c++17";
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_LINK_OBJC_RUNTIME = NO;
 				CODE_SIGN_ENTITLEMENTS = "App.entitlements";
@@ -601,7 +601,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ARCHS = "$(ARCHS_STANDARD_64_BIT)";
-				CLANG_CXX_LANGUAGE_STANDARD = "c++20";
+				CLANG_CXX_LANGUAGE_STANDARD = "c++17";
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_LINK_OBJC_RUNTIME = NO;
 				CODE_SIGN_ENTITLEMENTS = "App.entitlements";