Add bssl::Span<T>::subspan and use it.
This roughly aligns with absl::Span<T>::subspan.
Bug: 132
Change-Id: Iaf29418c1b10e2d357763dec90b6cb1371b86c3b
Reviewed-on: https://boringssl-review.googlesource.com/20824
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Martin Kreichgauer <martinkr@google.com>
diff --git a/include/openssl/span.h b/include/openssl/span.h
index d447314..97361c2 100644
--- a/include/openssl/span.h
+++ b/include/openssl/span.h
@@ -22,6 +22,7 @@
extern "C++" {
#include <algorithm>
+#include <cstdlib>
#include <type_traits>
namespace bssl {
@@ -104,6 +105,8 @@
std::is_convertible<decltype(std::declval<C>().data()), T *>::value &&
std::is_integral<decltype(std::declval<C>().size())>::value>;
+ static const size_t npos = -1;
+
public:
constexpr Span() : Span(nullptr, 0) {}
constexpr Span(T *ptr, size_t len) : data_(ptr), size_(len) {}
@@ -124,6 +127,7 @@
T *data() const { return data_; }
size_t size() const { return size_; }
+ bool empty() const { return size_ == 0; }
T *begin() const { return data_; }
const T *cbegin() const { return data_; }
@@ -133,12 +137,22 @@
T &operator[](size_t i) const { return data_[i]; }
T &at(size_t i) const { return data_[i]; }
+ Span subspan(size_t pos = 0, size_t len = npos) const {
+ if (pos > size_) {
+ abort(); // absl::Span throws an exception here.
+ }
+ return Span(data_ + pos, std::min(size_ - pos, len));
+ }
+
private:
T *data_;
size_t size_;
};
template <typename T>
+const size_t Span<T>::npos;
+
+template <typename T>
Span<T> MakeSpan(T *ptr, size_t size) {
return Span<T>(ptr, size);
}
