AK: Span: Allow slicing with zero length.

Previously, the following would not work:

    Bytes{}.slice(0);

because it was asserted that `start < size()`.

1 files changed, 10 insertions, 6 deletions

diff --git a/AK/Span.h b/AK/Span.h
index ec62904313..e6b0d74f61 100644
--- a/AK/Span.h
+++ b/AK/Span.h
@@ -142,16 +142,20 @@ public:
 
     ALWAYS_INLINE bool is_empty() const { return this->m_size == 0; }
 
-    ALWAYS_INLINE Span slice(size_t start, size_t size) const
+    ALWAYS_INLINE Span slice(size_t start, size_t length) const
     {
-        ASSERT(start + size <= this->m_size);
-        return { this->m_values + start, size };
+        ASSERT(start + length <= size());
+        return { this->m_values + start, length };
     }
-
     ALWAYS_INLINE Span slice(size_t start) const
     {
-        ASSERT(start < this->m_size);
-        return { this->m_values + start, this->m_size - start };
+        ASSERT(start <= size());
+        return { this->m_values + start, size() - start };
+    }
+
+    ALWAYS_INLINE Span trim(size_t length) const
+    {
+        return { this->m_values, min(size(), length) };
     }
 
     ALWAYS_INLINE T* offset(size_t start) const