Add Optional::value_type

[folly.git] / folly / gen / Base-inl.h

diff --git a/folly/gen/Base-inl.h b/folly/gen/Base-inl.h
index 0c4e92f4556959aff2f6a17d994eb595e86c9ae3..7eded731b8e49d3e950ecf839c076ea72d3b4dbb 100644 (file)
--- a/folly/gen/Base-inl.h
+++ b/folly/gen/Base-inl.h
@@ -559,7 +559,8 @@ class Filter : public Operator<Filter<Predicate>> {
     template <class Body>
     void foreach(Body&& body) const {
       source_.foreach([&](Value value) {
-        if (pred_(std::forward<Value>(value))) {
+        // NB: Argument not forwarded to avoid accidental move-construction
+        if (pred_(value)) {
           body(std::forward<Value>(value));
         }
       });
@@ -568,7 +569,8 @@ class Filter : public Operator<Filter<Predicate>> {
     template <class Handler>
     bool apply(Handler&& handler) const {
       return source_.apply([&](Value value) -> bool {
-        if (pred_(std::forward<Value>(value))) {
+        // NB: Argument not forwarded to avoid accidental move-construction
+        if (pred_(value)) {
           return handler(std::forward<Value>(value));
         }
         return true;
@@ -2306,7 +2308,13 @@ constexpr detail::Indirect indirect{};
 
 constexpr detail::Unwrap unwrap{};
 
-inline detail::Take take(size_t count) { return detail::Take(count); }
+template <class Number>
+inline detail::Take take(Number count) {
+  if (count < 0) {
+    throw std::invalid_argument("Negative value passed to take()");
+  }
+  return detail::Take(static_cast<size_t>(count));
+}
 
 inline detail::Stride stride(size_t s) { return detail::Stride(s); }