chaiscript_eval: Fix warning by replacing lambda with ternary operator expression

CTerasa-ep · CTerasa-ep · commit b44b987d4b93 · 2025-02-19T20:04:17.000+01:00
Using GCC 13.3.0 I get warnings like the following:

```
In file included from .../ChaiScript/static_libs/../include/chaiscript/language/chaiscript_optimizer.hpp:10,
                 from .../ChaiScript/static_libs/../include/chaiscript/language/chaiscript_parser.hpp:26,
                 from .../ChaiScript/static_libs/chaiscript_parser.cpp:1:
.../ChaiScript/static_libs/../include/chaiscript/language/chaiscript_eval.hpp: In instantiation of ‘chaiscript::Boxed_Value chaiscript::eval::Global_Decl_AST_Node&lt;T&gt;::eval_internal(const chaiscript::detail::Dispatch_State&amp;) const [with T = chaiscript::eval::Tracer&lt;chaiscript::eval::Noop_Tracer_Detail&gt;]’:
.../ChaiScript/static_libs/../include/chaiscript/language/chaiscript_eval.hpp:503:19:   required from here
.../ChaiScript/static_libs/../include/chaiscript/language/chaiscript_eval.hpp:504:28: warning: possibly dangling reference to a temporary [-Wdangling-reference]
  504 |         const std::string &amp;idname = [&amp;]() -&gt; const std::string &amp; {
      |                            ^~~~~~
.../ChaiScript/static_libs/../include/chaiscript/language/chaiscript_eval.hpp:510:10: note: the temporary was destroyed at the end of the full expression ‘&lt;lambda closure object&gt;chaiscript::eval::Global_Decl_AST_Node&lt;chaiscript::eval::Tracer&lt;chaiscript::eval::Noop_Tracer_Detail&gt; &gt;::eval_internal(const chaiscript::detail::Dispatch_State&amp;) const::&lt;lambda()&gt;{((const chaiscript::eval::Global_Decl_AST_Node&lt;chaiscript::eval::Tracer&lt;chaiscript::eval::Noop_Tracer_Detail&gt; &gt;*)this)}.chaiscript::eval::Global_Decl_AST_Node&lt;chaiscript::eval::Tracer&lt;chaiscript::eval::Noop_Tracer_Detail&gt; &gt;::eval_internal(const chaiscript::detail::Dispatch_State&amp;) const::&lt;lambda()&gt;()’
  504 |         const std::string &amp;idname = [&amp;]() -&gt; const std::string &amp; {
      |                                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  505 |           if (this-&gt;children[0]-&gt;identifier == AST_Node_Type::Reference) {
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  506 |             return this-&gt;children[0]-&gt;children[0]-&gt;text;
      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  507 |           } else {
      |           ~~~~~~~~
  508 |             return this-&gt;children[0]-&gt;text;
      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  509 |           }
      |           ~
  510 |         }();
      |         ~^~
```

Fix this by replacing the lambda with a simple ternary operator
expression.
diff --git a/include/chaiscript/language/chaiscript_eval.hpp b/include/chaiscript/language/chaiscript_eval.hpp
@@ -501,13 +501,7 @@ namespace chaiscript {
       }
 
       Boxed_Value eval_internal(const chaiscript::detail::Dispatch_State &t_ss) const override {
-        const std::string &idname = [&]() -> const std::string & {
-          if (this->children[0]->identifier == AST_Node_Type::Reference) {
-            return this->children[0]->children[0]->text;
-          } else {
-            return this->children[0]->text;
-          }
-        }();
+        const std::string &idname = (this->children[0]->identifier == AST_Node_Type::Reference) ? this->children[0]->children[0]->text : this->children[0]->text;
 
         return t_ss->add_global_no_throw(Boxed_Value(), idname);
       }

Original file line number	Diff line number	Diff line change
`@@ -501,13 +501,7 @@ namespace chaiscript {`
`501`	`501`	`}`
`502`	`502`
`503`	`503`	`Boxed_Value eval_internal(const chaiscript::detail::Dispatch_State &t_ss) const override {`
`504`		`- const std::string &idname = [&]() -> const std::string & {`
`505`		`- if (this->children[0]->identifier == AST_Node_Type::Reference) {`
`506`		`- return this->children[0]->children[0]->text;`
`507`		`- } else {`
`508`		`- return this->children[0]->text;`
`509`		`- }`
`510`		`- }();`
	`504`	`+ const std::string &idname = (this->children[0]->identifier == AST_Node_Type::Reference) ? this->children[0]->children[0]->text : this->children[0]->text;`
`511`	`505`
`512`	`506`	`return t_ss->add_global_no_throw(Boxed_Value(), idname);`
`513`	`507`	`}`