[core] Improve typing for !=, == expressions

1 files changed, 31 insertions, 0 deletions

diff --git a/include/mbgl/style/expression/equals.hpp b/include/mbgl/style/expression/equals.hpp
new file mode 100644
index 0000000000..3c0c024294
--- /dev/null
+++ b/include/mbgl/style/expression/equals.hpp
@@ -0,0 +1,31 @@
+#pragma once
+
+#include <mbgl/style/expression/expression.hpp>
+#include <mbgl/style/expression/parsing_context.hpp>
+#include <mbgl/style/conversion.hpp>
+
+#include <memory>
+
+namespace mbgl {
+namespace style {
+namespace expression {
+
+class Equals : public Expression {
+public:
+    Equals(std::unique_ptr<Expression> lhs, std::unique_ptr<Expression> rhs, bool negate);
+
+    static ParseResult parse(const mbgl::style::conversion::Convertible&, ParsingContext&);
+
+    void eachChild(const std::function<void(const Expression&)>& visit) const override;
+    bool operator==(const Expression&) const override;
+    EvaluationResult evaluate(const EvaluationContext&) const override;
+
+private:
+    std::unique_ptr<Expression> lhs;
+    std::unique_ptr<Expression> rhs;
+    bool negate;
+};
+
+} // namespace expression
+} // namespace style
+} // namespace mbgl