Add support for std::variant<..>

sharkdp · Jul 7, 2019 · 0e76f6a · hmenke · Jul 9, 2019 · hmenke
1 parent 3dd500a
commit 0e76f6a
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Showing 2 changed files with 35 additions and 15 deletions.
diff --git a/dbg.h b/dbg.h
@@ -48,6 +48,7 @@ License (MIT):
 
 #if __cplusplus >= 201703L
 #include <optional>
+#include <variant>
 #endif
 
 namespace dbg_macro {
@@ -328,21 +329,6 @@ bool pretty_print(std::ostream& stream, const std::tuple<>& value) {
   return true;
 }
 
-#if __cplusplus >= 201703L
-
-template <typename T>
-bool pretty_print(std::ostream& stream, const std::optional<T>& value) {
-  if (value) {
-    stream << '{' << *value << '}';
-  } else {
-    stream << "nullopt";
-  }
-
-  return true;
-}
-
-#endif  // __cplusplus >= 201703L
-
 template <typename Container>
 typename std::enable_if<detail::has_begin_end_size<const Container&>::value,
                         bool>::type
@@ -384,6 +370,30 @@ inline bool pretty_print(std::ostream& stream, const std::string& value) {
   return true;
 }
 
+#if __cplusplus >= 201703L
+
+template <typename T>
+bool pretty_print(std::ostream& stream, const std::optional<T>& value) {
+  if (value) {
+    stream << '{' << *value << '}';
+  } else {
+    stream << "nullopt";
+  }
+
+  return true;
+}
+
+template <typename... Ts>
+bool pretty_print(std::ostream& stream, const std::variant<Ts...>& value) {
+  stream << "{";
+  std::visit([&stream](auto&& arg) { pretty_print(stream, arg); }, value);
+  stream << "}";
+
+  return true;
+}
+
+#endif  // __cplusplus >= 201703L
+
 class DebugOutput {
  public:
   DebugOutput(const char* filepath,

diff --git a/tests/tests.cpp b/tests/tests.cpp
@@ -7,6 +7,11 @@
 #include <tuple>
 #include <vector>
 
+#if __cplusplus >= 201703L
+#include <optional>
+#include <variant>
+#endif
+
 #include <dbg.h>
 
 template <typename L, typename R>
@@ -197,6 +202,11 @@ int main() {
   assert_eq(pretty_print(std::make_optional<int>(42)), "{42}");
   std::optional<int> empty_optional;
   assert_eq(pretty_print(empty_optional), "nullopt");
+
+  std::variant<int, std::string> dummy_variant = "test";
+  assert_eq(pretty_print(dummy_variant), "{\"test\"}");
+  dummy_variant = 42;
+  assert_eq(pretty_print(dummy_variant), "{42}");
 #endif
 
   dbg("====== type_name<T>() tests");