From cb5967d8f46fbba7c7e30f436032fef0ed671fe9 Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Mon, 4 Nov 2024 18:11:37 +0100
Subject: More work on span

---
 asl/span.hpp | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

(limited to 'asl/span.hpp')

diff --git a/asl/span.hpp b/asl/span.hpp
index f3d4036..efc9eec 100644
--- a/asl/span.hpp
+++ b/asl/span.hpp
@@ -3,6 +3,7 @@
 #include "asl/meta.hpp"
 #include "asl/annotations.hpp"
 #include "asl/layout.hpp"
+#include "asl/assert.hpp"
 
 namespace asl
 {
@@ -22,6 +23,46 @@ class span
 public:
     constexpr span() = default;
 
+    constexpr span(T* data, int64_t size)
+        requires kIsDynamic
+        : m_data{data}
+        , m_size{size}
+    {}
+
+    constexpr explicit span(T* data, int64_t size)
+        requires (!kIsDynamic)
+        : m_data{data}
+    {
+        ASL_ASSERT(size == kSize);
+    }
+
+    template<int64_t N>
+    constexpr span(T (&array)[N]) // NOLINT(*-explicit-conversions)
+        requires (kIsDynamic)
+        : m_data{array}
+        , m_size{N}
+    {}
+
+    template<int64_t N>
+    constexpr span(T (&array)[N]) // NOLINT(*-explicit-conversions)
+        requires (!kIsDynamic) && (N == kSize)
+        : m_data{array}
+    {}
+
+    template<is_object U, int64_t kOtherSize>
+    constexpr explicit(!kIsDynamic)
+    span(const span<U, kOtherSize>& other) // NOLINT(*-explicit-conversions)
+        requires (
+            (
+                kIsDynamic ||
+                span<U, kOtherSize>::kIsDynamic ||
+                kOtherSize == kSize
+            ) && convertible_from<T(&)[], U(&)[]>
+        )
+        : span{static_cast<U*>(other.data()), other.size()}
+    {
+    }
+
     constexpr span(const span&) = default;
     constexpr span(span&&) = default;
     
@@ -39,6 +80,23 @@ public:
     constexpr int64_t size_bytes() const { return size() * size_of<T>; }
 
     constexpr bool is_empty() const { return size() == 0; }
+
+    constexpr T* data() const { return m_data; }
+
+    constexpr T* begin() const { return m_data; }
+    constexpr T* end() const { return m_data + size(); }
+
+    constexpr T& operator[](int64_t i) const
+    {
+        ASL_ASSERT(i >= 0 && i < size());
+        return m_data[i]; // NOLINT(*-pointer-arithmetic)
+    }
+
+    // @Todo subspan, first, last
+    // @Todo as_(mutable_)bytes
+
+    template<is_object U, int64_t kOtherSize>
+    friend class span;
 };
 
 } // namespace asl
-- 
cgit