Use std::string_view for @Cpp(ToString) on enums (#1479)

Signed-off-by: Daniel Kamkha <[email protected]> Signed-off-by: Daniel Kamkha <[email protected]>
heremaps · Aug 25, 2022 · e9af39d · e9af39d
1 parent 0724189
commit e9af39d
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Showing 7 changed files with 16 additions and 20 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Gluecodium project Release Notes
 
+## Unreleased
+### Breaking changes:
+  * C++ enum function `to_string()` generated by `@Cpp(ToString)` attribute returns `std::string_view` now.
+
 ## 13.3.2
 Release date: 2022-08-25
 ### Bug fixes:

diff --git a/gluecodium/src/main/java/com/here/gluecodium/generator/cpp/CppIncludeResolver.kt b/gluecodium/src/main/java/com/here/gluecodium/generator/cpp/CppIncludeResolver.kt
@@ -24,7 +24,7 @@ import com.here.gluecodium.generator.common.Include
 import com.here.gluecodium.model.lime.LimeAttributeType.ASYNC
 import com.here.gluecodium.model.lime.LimeAttributeType.CPP
 import com.here.gluecodium.model.lime.LimeAttributeType.OPTIMIZED
-import com.here.gluecodium.model.lime.LimeAttributeValueType
+import com.here.gluecodium.model.lime.LimeAttributeValueType.TO_STRING
 import com.here.gluecodium.model.lime.LimeBasicType
 import com.here.gluecodium.model.lime.LimeBasicType.TypeId
 import com.here.gluecodium.model.lime.LimeContainerWithInheritance
@@ -72,15 +72,13 @@ internal class CppIncludeResolver(
             is LimeFunction -> resolveFunctionIncludes(limeElement)
             is LimeLambda -> cppIncludesCache.resolveIncludes(limeElement) + CppLibraryIncludes.FUNCTIONAL
             is LimeNamedElement -> cppIncludesCache.resolveIncludes(limeElement) +
-                if (limeElement.attributes.have(CPP, LimeAttributeValueType.TO_STRING)) listOf(CppLibraryIncludes.STRING)
-                else emptyList()
+                listOfNotNull(CppLibraryIncludes.STRING_VIEW.takeIf { limeElement.attributes.have(CPP, TO_STRING) })
             else -> emptyList()
         }
 
     private fun resolveFunctionIncludes(limeFunction: LimeFunction) =
         resolveExceptionIncludes(limeFunction) +
-            if (limeFunction.attributes.have(ASYNC)) listOf(CppLibraryIncludes.FUNCTIONAL)
-            else emptyList()
+            listOfNotNull(CppLibraryIncludes.FUNCTIONAL.takeIf { limeFunction.attributes.have(ASYNC) })
 
     private fun resolveExceptionIncludes(limeFunction: LimeFunction): List<Include> {
         val payloadType = limeFunction.exception?.errorType?.type?.actualType ?: return emptyList()
@@ -89,10 +87,7 @@ internal class CppIncludeResolver(
                 if (limeFunction.attributes.have(ASYNC)) cppIncludesCache.resolveIncludes(payloadType) else emptyList()
             is LimeBasicType -> listOf(returnInclude)
             else -> cppIncludesCache.resolveIncludes(payloadType) + returnInclude
-        } + when {
-            limeFunction.returnType.isVoid -> emptyList()
-            else -> listOf(returnInclude)
-        }
+        } + listOfNotNull(returnInclude.takeIf { !limeFunction.returnType.isVoid })
     }
 
     private fun resolveValueIncludes(limeValue: LimeValue): List<Include> =
@@ -123,11 +118,7 @@ internal class CppIncludeResolver(
             TypeId.DATE -> listOf(CppLibraryIncludes.CHRONO, timePointHashInclude)
             TypeId.DURATION -> listOf(CppLibraryIncludes.CHRONO, durationHashInclude)
             TypeId.LOCALE -> listOf(localeInclude)
-            TypeId.BLOB -> listOf(
-                CppLibraryIncludes.MEMORY,
-                CppLibraryIncludes.VECTOR,
-                CppLibraryIncludes.INT_TYPES
-            )
+            TypeId.BLOB -> listOf(CppLibraryIncludes.MEMORY, CppLibraryIncludes.VECTOR, CppLibraryIncludes.INT_TYPES)
             else -> emptyList()
         }
     }

diff --git a/gluecodium/src/main/java/com/here/gluecodium/generator/cpp/CppLibraryIncludes.kt b/gluecodium/src/main/java/com/here/gluecodium/generator/cpp/CppLibraryIncludes.kt
@@ -29,6 +29,7 @@ object CppLibraryIncludes {
     val MAP = Include.createSystemInclude("unordered_map")
     val MEMORY = Include.createSystemInclude("memory")
     val STRING = Include.createSystemInclude("string")
+    val STRING_VIEW = Include.createSystemInclude("string_view")
     val VECTOR = Include.createSystemInclude("vector")
     val NEW = Include.createSystemInclude("new")
     val SYSTEM_ERROR = Include.createSystemInclude("system_error")

diff --git a/gluecodium/src/main/resources/templates/cpp/CppEnumeration.mustache b/gluecodium/src/main/resources/templates/cpp/CppEnumeration.mustache
@@ -28,7 +28,7 @@ enum class {{>cpp/CppAttributesInline}}{{resolveName}} {
 };
 
 {{#if attributes.cpp.tostring}}
-std::string
+std::string_view
 {{>cpp/CppExportMacro}}to_string({{resolveName}} enumeration);
 {{/if}}
 {{/unless}}
diff --git a/gluecodium/src/main/resources/templates/cpp/CppEnumerationImpl.mustache b/gluecodium/src/main/resources/templates/cpp/CppEnumerationImpl.mustache
@@ -30,7 +30,7 @@ static_assert(
 {{/if}}
 
 {{#if attributes.cpp.tostring}}
-  std::string
+  std::string_view
   to_string({{resolveName}} enumeration) {
     switch (enumeration) {
     {{#set enum=this}}{{#enumerators}}

diff --git a/gluecodium/src/test/resources/smoke/enums/output/cpp/include/smoke/EnumWithToStringHelper.h b/gluecodium/src/test/resources/smoke/enums/output/cpp/include/smoke/EnumWithToStringHelper.h
@@ -5,12 +5,12 @@
 #pragma once
 #include "gluecodium/ExportGluecodiumCpp.h"
 #include <cstdint>
-#include <string>
+#include <string_view>
 namespace smoke {
 enum class EnumWithToStringHelper {
     FIRST,
     SECOND
 };
-std::string
+std::string_view
 _GLUECODIUM_CPP_EXPORT to_string(EnumWithToStringHelper enumeration);
 }
diff --git a/gluecodium/src/test/resources/smoke/enums/output/cpp/src/smoke/EnumWithToStringHelper.cpp b/gluecodium/src/test/resources/smoke/enums/output/cpp/src/smoke/EnumWithToStringHelper.cpp
@@ -2,9 +2,9 @@
 //
 //
 // -------------------------------------------------------------------------------------------------
-#include "smoke\EnumWithToStringHelper.h"
+#include "smoke/EnumWithToStringHelper.h"
 namespace smoke {
-  std::string
+  std::string_view
   to_string(EnumWithToStringHelper enumeration) {
     switch (enumeration) {
       case EnumWithToStringHelper::FIRST: return "EnumWithToStringHelper::FIRST";