From 41c0ac0fddd8bbaa9b0be7e572d0460731fb3ef8 Mon Sep 17 00:00:00 2001
From: q66 <daniel@octaforge.org>
Date: Sun, 28 Jun 2015 22:16:13 +0100
Subject: [PATCH] return a pointer from the "at" methods (which is nullptr on
 non-existent items)

---
 octa/array.hh   | 10 ++++++++--
 octa/vector.hh  | 10 ++++++++--
 tests/array.cc  |  4 ++--
 tests/vector.cc |  4 ++--
 4 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/octa/array.hh b/octa/array.hh
index e06c937..a8508f1 100644
--- a/octa/array.hh
+++ b/octa/array.hh
@@ -29,8 +29,14 @@ struct Array {
     T &operator[](Size i) { return p_buf[i]; }
     const T &operator[](Size i) const { return p_buf[i]; }
 
-    T &at(Size i) { return p_buf[i]; }
-    const T &at(Size i) const { return p_buf[i]; }
+    T *at(Size i) {
+        if (!in_range(i)) return nullptr;
+        return &p_buf[i];
+    }
+    const T *at(Size i) const {
+        if (!in_range(i)) return nullptr;
+        return &p_buf[i];
+    }
 
     T &front() { return p_buf[0]; }
     const T &front() const { return p_buf[0]; }
diff --git a/octa/vector.hh b/octa/vector.hh
index cce4f39..f5da0c2 100644
--- a/octa/vector.hh
+++ b/octa/vector.hh
@@ -288,8 +288,14 @@ public:
     T &operator[](Size i) { return p_buf.first()[i]; }
     const T &operator[](Size i) const { return p_buf.first()[i]; }
 
-    T &at(Size i) { return p_buf.first()[i]; }
-    const T &at(Size i) const { return p_buf.first()[i]; }
+    T *at(Size i) {
+        if (!in_range(i)) return nullptr;
+        return &p_buf.first()[i];
+    }
+    const T *at(Size i) const {
+        if (!in_range(i)) return nullptr;
+        return &p_buf.first()[i];
+    }
 
     T &push(const T &v) {
         if (p_len == p_cap) reserve(p_len + 1);
diff --git a/tests/array.cc b/tests/array.cc
index 558f90f..66b4619 100644
--- a/tests/array.cc
+++ b/tests/array.cc
@@ -14,8 +14,8 @@ int main() {
     assert(x[0] == 2);
     assert(x[2] == 8);
 
-    assert(x.at(0) == x[0]);
-    assert(x.at(3) == x[3]);
+    assert(*(x.at(0)) == x[0]);
+    assert(*(x.at(3)) == x[3]);
 
     assert(x.size() == 5);
 
diff --git a/tests/vector.cc b/tests/vector.cc
index f6c34a1..8a7c8d6 100644
--- a/tests/vector.cc
+++ b/tests/vector.cc
@@ -14,8 +14,8 @@ int main() {
     assert(x[0] == 5);
     assert(x[2] == 15);
 
-    assert(x.at(0) == x[0]);
-    assert(x.at(3) == x[3]);
+    assert(*(x.at(0)) == x[0]);
+    assert(*(x.at(3)) == x[3]);
 
     assert(x.data()[0] == x[0]);