Create is_valid_type function

3 files changed, 20 insertions, 0 deletions

diff --git a/include/tag.h b/include/tag.h
index 75a41f2e1f..ae84891c76 100644
--- a/include/tag.h
+++ b/include/tag.h
@@ -45,6 +45,12 @@ enum class tag_type : int8_t
     Null = -1   ///< Used to denote empty @ref value s
 };
 
+/**
+ * @brief Returns whether the given number falls within the range of valid tag types
+ * @param allow_end whether to consider tag_type::End (0) valid
+ */
+bool is_valid_type(int type, bool allow_end = false);
+
 ///Base class for all NBT tag classes
 class tag
 {
diff --git a/src/tag.cpp b/src/tag.cpp
index b695bd98bb..db4c09aa2e 100644
--- a/src/tag.cpp
+++ b/src/tag.cpp
@@ -26,6 +26,11 @@
 namespace nbt
 {
 
+bool is_valid_type(int type, bool allow_end)
+{
+    return (allow_end ? 0 : 1) <= type && type <= 11;
+}
+
 std::unique_ptr<tag> tag::clone() &&
 {
     return std::move(*this).move_clone();
diff --git a/test/nbttest.cpp b/test/nbttest.cpp
index 12f80ed62e..15b0c67fba 100644
--- a/test/nbttest.cpp
+++ b/test/nbttest.cpp
@@ -26,6 +26,15 @@ using namespace nbt;
 
 void test_tag()
 {
+    ASSERT(!is_valid_type(-1));
+    ASSERT(!is_valid_type(0));
+    ASSERT(is_valid_type(0, true));
+    ASSERT(is_valid_type(1));
+    ASSERT(is_valid_type(5, false));
+    ASSERT(is_valid_type(7, true));
+    ASSERT(is_valid_type(11));
+    ASSERT(!is_valid_type(12));
+
     ASSERT(*tag::create(tag_type::Byte) == tag_byte());
     EXPECT_EXCEPTION(tag::create(tag_type::Null), std::invalid_argument);
     EXPECT_EXCEPTION(tag::create(tag_type::End), std::invalid_argument);