From dfdeda17fdf3901be538d741159bacaf8ec999ef Mon Sep 17 00:00:00 2001
From: Artem Pavlenko <artem@mapnik.org>
Date: Wed, 13 Nov 2024 14:03:01 +0000
Subject: [PATCH] expressions  - add "bool(expr)" explicit conversion operator

---
 include/mapnik/expression_grammar_x3_def.hpp | 1 +
 include/mapnik/function_call.hpp             | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/include/mapnik/expression_grammar_x3_def.hpp b/include/mapnik/expression_grammar_x3_def.hpp
index 06a318698..5b1dc9583 100644
--- a/include/mapnik/expression_grammar_x3_def.hpp
+++ b/include/mapnik/expression_grammar_x3_def.hpp
@@ -217,6 +217,7 @@ struct unary_function_types_ : x3::symbols<unary_function_impl>
           ("log", log_impl())       //
           ("abs", abs_impl())       //
           ("length", length_impl()) //
+          ("bool", bool_impl())     //
           ("int", int_impl())       //
           ("float", float_impl())   //
           ("str", str_impl())       //
diff --git a/include/mapnik/function_call.hpp b/include/mapnik/function_call.hpp
index 30e8b956d..75c92a1e8 100644
--- a/include/mapnik/function_call.hpp
+++ b/include/mapnik/function_call.hpp
@@ -95,6 +95,12 @@ struct str_impl
     value_type operator()(value_type const& val) const { return val.to_unicode(); }
 };
 
+// bool
+struct bool_impl
+{
+    value_type operator()(value_type const& val) const { return val.to_bool(); }
+};
+
 // int
 struct int_impl
 {