1 files changed, 21 insertions, 0 deletions
diff --git a/vendor/serde/src/private/size_hint.rs b/vendor/serde/src/private/size_hint.rs
new file mode 100644
index 000000000..ca71e616b
--- /dev/null
+++ b/vendor/serde/src/private/size_hint.rs
@@ -0,0 +1,21 @@
+use lib::*;
+
+pub fn from_bounds<I>(iter: &I) -> Option<usize>
+where
+    I: Iterator,
+{
+    helper(iter.size_hint())
+}
+
+#[cfg(any(feature = "std", feature = "alloc"))]
+#[inline]
+pub fn cautious(hint: Option<usize>) -> usize {
+    cmp::min(hint.unwrap_or(0), 4096)
+}
+
+fn helper(bounds: (usize, Option<usize>)) -> Option<usize> {
+    match bounds {
+        (lower, Some(upper)) if lower == upper => Some(upper),
+        _ => None,
+    }
+}