1 files changed, 4 insertions, 0 deletions
diff --git a/include/mbgl/style/expression/dsl.hpp b/include/mbgl/style/expression/dsl.hpp
index 8a5d1d84f5..22278b0975 100644
--- a/include/mbgl/style/expression/dsl.hpp
+++ b/include/mbgl/style/expression/dsl.hpp
@@ -5,6 +5,7 @@
 #include <mbgl/style/expression/interpolator.hpp>
 
 #include <memory>
+#include <string>
 #include <initializer_list>
 
 namespace mbgl {
@@ -15,6 +16,8 @@ namespace dsl {
 // This convenience API does little to no expression validation or type-checking, and is intended for
 // use only by test and other non-production code.
 
+std::unique_ptr<Expression> error(std::string);
+
 std::unique_ptr<Expression> literal(const char* value);
 std::unique_ptr<Expression> literal(Value value);
 std::unique_ptr<Expression> literal(std::initializer_list<double> value);
@@ -22,6 +25,7 @@ std::unique_ptr<Expression> literal(std::initializer_list<const char *> value);
 
 std::unique_ptr<Expression> number(std::unique_ptr<Expression>);
 std::unique_ptr<Expression> string(std::unique_ptr<Expression>);
+std::unique_ptr<Expression> boolean(std::unique_ptr<Expression>);
 
 std::unique_ptr<Expression> toColor(const char* value);
 std::unique_ptr<Expression> toColor(std::unique_ptr<Expression>);