From 004c9d8d0912d55960fd9c7f8b76572fcf1a5804 Mon Sep 17 00:00:00 2001
From: Joel Rosdahl <joel@rosdahl.net>
Date: Sun, 26 Oct 2025 09:29:40 +0100
Subject: [PATCH] enhance: Add util::Bytes::at method

---
 src/ccache/util/bytes.cpp    | 20 ++++++++++++++++++++
 src/ccache/util/bytes.hpp    |  3 +++
 unittest/test_util_bytes.cpp | 24 ++++++++++++++++++++++++
 3 files changed, 47 insertions(+)

diff --git a/src/ccache/util/bytes.cpp b/src/ccache/util/bytes.cpp
index 3bb76183..d3c82f43 100644
--- a/src/ccache/util/bytes.cpp
+++ b/src/ccache/util/bytes.cpp
@@ -20,6 +20,8 @@
 
 #include <ccache/util/assertions.hpp>
 
+#include <stdexcept>
+
 namespace util {
 
 namespace {
@@ -92,6 +94,24 @@ Bytes::operator=(std::string_view data) noexcept
   return *this;
 }
 
+uint8_t
+Bytes::at(size_t pos) const
+{
+  if (pos >= m_size) {
+    throw std::out_of_range("Bytes::at: pos >= size()");
+  }
+  return m_data[pos];
+}
+
+uint8_t&
+Bytes::at(size_t pos)
+{
+  if (pos >= m_size) {
+    throw std::out_of_range("Bytes::at: pos >= size()");
+  }
+  return m_data[pos];
+}
+
 void
 Bytes::reserve(size_t size) noexcept
 {
diff --git a/src/ccache/util/bytes.hpp b/src/ccache/util/bytes.hpp
index d7545e2a..56d394f3 100644
--- a/src/ccache/util/bytes.hpp
+++ b/src/ccache/util/bytes.hpp
@@ -60,6 +60,9 @@ public:
   uint8_t operator[](size_t pos) const noexcept;
   uint8_t& operator[](size_t pos) noexcept;
 
+  uint8_t at(size_t pos) const;
+  uint8_t& at(size_t pos);
+
   bool operator==(const Bytes& other) const noexcept;
   bool operator!=(const Bytes& other) const noexcept;
 
diff --git a/unittest/test_util_bytes.cpp b/unittest/test_util_bytes.cpp
index c3a320c6..cc3bf3d6 100644
--- a/unittest/test_util_bytes.cpp
+++ b/unittest/test_util_bytes.cpp
@@ -189,6 +189,30 @@ TEST_CASE("Basics")
     CHECK(bytes1[1] == 'x'); // cppcheck-suppress knownConditionTrueFalse
   }
 
+  SUBCASE("at method")
+  {
+    // Const version
+    const Bytes& const_bytes = bytes1;
+    CHECK(const_bytes.at(0) == 'a');
+    CHECK(const_bytes.at(1) == 'b');
+    CHECK(const_bytes.at(2) == 'c');
+    CHECK_THROWS_AS(const_bytes.at(3), std::out_of_range);
+    CHECK_THROWS_AS(const_bytes.at(100), std::out_of_range);
+
+    // Non-const version
+    CHECK(bytes1.at(0) == 'a');
+    CHECK(bytes1.at(1) == 'b');
+    CHECK(bytes1.at(2) == 'c');
+    bytes1.at(1) = 'x';
+    CHECK(bytes1.at(1) == 'x');
+    CHECK_THROWS_AS(bytes1.at(3), std::out_of_range);
+    CHECK_THROWS_AS(bytes1.at(100), std::out_of_range);
+
+    // Empty
+    Bytes empty;
+    CHECK_THROWS_AS(empty.at(0), std::out_of_range);
+  }
+
   SUBCASE("Comparison")
   {
     CHECK(bytes1 == bytes1);
-- 
2.47.3