Dev

.clang-format

@@ -3,4 +3,4 @@ IndentWidth: 4
 Language: Cpp
 PointerAlignment: Left
 BreakBeforeBraces: Stroustrup
-ColumnLimit: 120
+ColumnLimit: 120

.devcontainer/Dockerfile

@@ -0,0 +1,51 @@
+# Use the official Ubuntu base image
+FROM ubuntu:20.04
+
+# Avoid interactive package installation
+ENV DEBIAN_FRONTEND=noninteractive
+
+# Install required packages
+RUN apt update && apt install -y \
+    build-essential \
+    cmake \
+    clang-tidy \
+    clang-format \
+    lcov \
+    git \
+    curl \
+    wget \
+    unzip \
+    python3 \
+    python3-pip \
+    gdb \
+    lldb \
+    clang \
+    llvm \
+    nano \
+    software-properties-common \
+    && rm -rf /var/lib/apt/lists/*
+
+# Create a non-root user
+ARG USERNAME=vscode
+ARG USER_UID=1000
+ARG USER_GID=$USER_UID
+
+RUN groupadd -g $USER_GID $USERNAME || true \
+    && useradd --uid $USER_UID --gid $USER_GID -m $USERNAME -s /bin/bash \
+    && apt update \
+    && apt install -y sudo \
+    && echo $USERNAME ALL=\(ALL\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME \
+    && chmod 0440 /etc/sudoers.d/$USERNAME
+
+# History
+RUN SNIPPET="export PROMPT_COMMAND='history -a' && export HISTFILE=/commandhistory/.bash_history" \
+    && mkdir /commandhistory \
+    && touch /commandhistory/.bash_history \
+    && chown -R $USERNAME /commandhistory \
+    && echo "$SNIPPET" >> "/home/$USERNAME/.bashrc"
+
+    # Set the user to vscode
+USER $USERNAME
+
+# Set the workspace directory
+WORKDIR /workspace

.devcontainer/devcontainer.json

@@ -0,0 +1,31 @@
+{
+    "name": "C++ Development with CMake and Bazel",
+    "dockerFile": "Dockerfile",
+    "customizations": {
+        "vscode": {
+            "extensions": [
+                "ms-vscode.cmake-tools",
+                "ms-vscode.cpptools",
+                "ms-vscode.cpptools-extension-pack",
+                "xaver.clang-format",
+                "twxs.cmake",
+                "fredericbonnet.cmake-test-adapter",
+                "ms-vscode.cmake-tools",
+                "notskm.clang-tidy",
+                "ryanluker.vscode-coverage-gutters",
+            ]
+        }
+    },
+    "mounts": [
+        "source=${localWorkspaceFolder},target=/workspace,type=bind,consistency=cached",
+        "source=${env:HOME}/.ssh,target=/home/vscode/.ssh,type=bind,consistency=cached",
+        "source=history,target=/commandhistory,type=volume"
+    ],
+    "workspaceFolder": "/workspace",
+    "runArgs": [
+        "--cap-add=SYS_PTRACE",
+        "--security-opt",
+        "seccomp=unconfined"
+    ],
+   "remoteUser": "vscode"
+}

.vscode/c_cpp_properties.json

@@ -17,7 +17,7 @@
                 "${workspaceFolder}/**"
             ],
             "defines": [],
-            "compilerPath": "/usr/bin/gcc-11",
+            "compilerPath": "/usr/bin/gcc-9",
             "cStandard": "c17",
             "intelliSenseMode": "linux-clang-x64",
             "configurationProvider": "ms-vscode.cmake-tools"

.vscode/extensions.json

@@ -1,12 +1,5 @@
 {
     "recommendations": [
-        "ms-vscode.cpptools",
-        "ms-vscode.cpptools-extension-pack",
-        "xaver.clang-format",
-        "twxs.cmake",
-        "fredericbonnet.cmake-test-adapter",
-        "ms-vscode.cmake-tools",
-        "notskm.clang-tidy",
-        "ryanluker.vscode-coverage-gutters",
+        "ms-vscode-remote.remote-containers",
     ]
 }

.vscode/settings.json

@@ -27,8 +27,11 @@
         "coverage.cobertura.xml"
     ],
     "C_Cpp.default.configurationProvider": "ms-vscode.cmake-tools",
+    "C_Cpp.codeAnalysis.clangTidy.enabled": true,
     "C_Cpp.codeAnalysis.clangTidy.useBuildPath": true,
-    "clang-tidy.buildPath": "build",
+    "C_Cpp.codeAnalysis.clangTidy.args": [
+        "-p=build"
+    ],
     "files.associations": {
         "array": "cpp",
         "*.tcc": "cpp",

.vscode/tasks.json

@@ -7,7 +7,7 @@
             "command": "mkdir -p build",
             "group": {
                 "kind": "build",
-                "isDefault": true
+                "isDefault": false
             },
             "options": {
                 "cwd": "${workspaceFolder}"
@@ -21,7 +21,7 @@
             "dependsOn": "Create build directory",
             "group": {
                 "kind": "build",
-                "isDefault": true
+                "isDefault": false
             },
             "options": {
                 "cwd": "${workspaceFolder}/build"
@@ -41,6 +41,16 @@
                 "cwd": "${workspaceFolder}/build"
             },
             "problemMatcher": []
-        }
+        },
+        {
+            "label": "Run clang-tidy on current file",
+            "type": "shell",
+            "command": "clang-tidy",
+            "args": [
+              "${file}",
+              "-p=build"
+            ],
+            "problemMatcher": ["$gcc"]
+          }
     ]
 }

README.md

@@ -47,20 +47,35 @@ int main() {
 
 ```
 
-See [tests](tests/zip_test.cpp).
+See [tests](tests/).
+
+## Development
+
+### Tools
+* [SSH keys for GitHub](https://help.ubuntu.com/community/SSH/OpenSSH/Keys) (~/.ssh)
+* [VS Code](https://code.visualstudio.com/) (see [.vscode/extensions.json](.vscode/extensions.json))
+* [Docker](https://docs.docker.com/engine/install/ubuntu/)
+
+### Actions
+* Debug: F5
+* Coverage: Ctrl + Shift + P -> Run Task -> Generate Coverage Report
+* Show coverage inline: Ctrl + Shift + 7 OR Ctrl + Shift + P -> Coverage Gutters: Display Coverage
+* Coverage as HTML: See build/coverage_html/index.html
 
 ## TODO
 
-* Write size() as end() - begin()
 * Exception guarantees
 * constexpr
 * const correctness
 * Write benchmarks
 * ContainersAndAlgorithms test fails at `EXPECT_EQ(it, std::prev(const_zip.end()));` for std::list
+    * Can the zip iterator really be bidirectional?
+    * Document or conditionaly set the iterator tag by the containers types
 * Consider checked access that returns an optional reference
-* List tools required for dev or create devcontainer
+* Do not allow to mix begin/end with cbegin/cend
+* Run clang-tidy, clang-format in CI/file save
 * Test
-    * 100% coverage
+    * Analyze if LCOV_EXCL_LINE is needed
     * Finish tests
     * With std algorithms
     * Entire API in non-const and const context

include/msd/zip.hpp

@@ -19,55 +19,77 @@ class zip_iterator {
     using pointer = std::tuple<typename std::iterator_traits<Iterators>::pointer...>;
     using reference = std::tuple<typename std::iterator_traits<Iterators>::reference...>;
 
-    explicit zip_iterator(Iterators... iterators) : iterators_{iterators...} {}
+    explicit zip_iterator(Iterators... iterators) noexcept : iterators_{iterators...} {}
 
-    value_type operator*() const { return dereference(std::index_sequence_for<Iterators...>{}); }
+    value_type operator*() const noexcept { return dereference(std::index_sequence_for<Iterators...>{}); }
 
-    bool operator==(const zip_iterator& other) const { return equal(std::index_sequence_for<Iterators...>{}, other); }
+    bool operator==(const zip_iterator& other) const noexcept
+    {
+        return equal(std::index_sequence_for<Iterators...>{}, other);
+    }
 
-    bool operator!=(const zip_iterator& other) const { return !equal(std::index_sequence_for<Iterators...>{}, other); }
+    bool operator!=(const zip_iterator& other) const noexcept
+    {
+        return !equal(std::index_sequence_for<Iterators...>{}, other);
+    }
 
     zip_iterator& operator++() noexcept
     {
         advance(std::index_sequence_for<Iterators...>{}, 1);
         return *this;
     }
 
+    zip_iterator operator+(const std::size_t offset) const noexcept
+    {
+        auto iterator = *this;
+        iterator.advance(std::index_sequence_for<Iterators...>{}, offset);
+        return iterator;
+    }
+
+    zip_iterator operator+(const zip_iterator& other) const noexcept
+    {
+        auto iterator = *this;
+        const auto distance = std::distance(iterator, other);
+        iterator.advance(std::index_sequence_for<Iterators...>{}, distance);
+        return iterator;
+    }
+
     zip_iterator& operator--() noexcept
     {
         advance(std::index_sequence_for<Iterators...>{}, -1);
         return *this;
     }
 
-    zip_iterator operator+(const std::size_t offset) const noexcept
+    zip_iterator operator-(const int offset) const noexcept
     {
         auto iterator = *this;
-        iterator.advance(std::index_sequence_for<Iterators...>{}, offset);
+        iterator.advance(std::index_sequence_for<Iterators...>{}, -offset);
         return iterator;
     }
 
-    zip_iterator operator-(const int offset) const noexcept
+    zip_iterator operator-(const zip_iterator& other) const noexcept
     {
         auto iterator = *this;
-        iterator.advance(std::index_sequence_for<Iterators...>{}, -offset);
+        const auto distance = std::distance(other, iterator);
+        iterator.advance(std::index_sequence_for<Iterators...>{}, -distance);
         return iterator;
     }
 
    private:
     template <std::size_t... I>
-    value_type dereference(std::index_sequence<I...>) const
+    value_type dereference(std::index_sequence<I...>) const noexcept
     {
         return std::tie(*std::get<I>(iterators_)...);
     }
 
     template <std::size_t... I>
-    bool equal(std::index_sequence<I...>, const zip_iterator& other) const
+    bool equal(std::index_sequence<I...>, const zip_iterator& other) const noexcept
     {
         return ((std::get<I>(iterators_) == std::get<I>(other.iterators_)) || ...);
     }
 
     template <std::size_t... I>
-    void advance(std::index_sequence<I...>, int offset)
+    void advance(std::index_sequence<I...>, const int offset) noexcept
     {
         ((std::advance(std::get<I>(iterators_), offset)), ...);
     }
@@ -86,7 +108,7 @@ class zip {
 
     using value_type = typename iterator::value_type;
 
-    explicit zip(Containers&... containers) : containers_{containers...} {}
+    explicit zip(Containers&... containers) noexcept : containers_{containers...} {}
 
     iterator begin() const { return begin_impl(std::index_sequence_for<Containers...>{}); }
     iterator end() const { return end_impl(std::index_sequence_for<Containers...>{}); }
@@ -108,7 +130,7 @@ class zip {
 
     value_type front() const
     {
-        assert(!empty());
+        assert(!empty());  // LCOV_EXCL_LINE
         return *begin();
     }
 
@@ -132,13 +154,13 @@ class zip {
 
    private:
     template <std::size_t... I>
-    iterator begin_impl(std::index_sequence<I...>) const
+    iterator begin_impl(std::index_sequence<I...>) const noexcept
     {
         return iterator{std::get<I>(containers_).begin()...};
     }
 
     template <std::size_t... I>
-    iterator end_impl(std::index_sequence<I...>) const
+    iterator end_impl(std::index_sequence<I...>) const noexcept
     {
         return std::next(iterator{std::get<I>(containers_).begin()...}, size());
     }

tests/zip_integration_test.cpp

@@ -6,7 +6,10 @@
 #include <forward_list>
 #include <iterator>
 #include <list>
+#include <map>
 #include <numeric>
+#include <set>
+#include <string>
 #include <unordered_map>
 #include <unordered_set>
 #include <vector>
@@ -19,7 +22,7 @@ TEST(ZipIntegrationTest, ContainersAndAlgorithms)
     std::deque<int> deque{1, 2};
     std::list<int> list{1, 2, 3};
     std::forward_list<int> forward_list{1, 2, 3, 4};
-    std::array<int, 5> array{1, 2, 3, 4, 5};
+    const std::array<int, 5> array{1, 2, 3, 4, 5};
     std::string string{"123456"};
     std::set<int> set{1, 2, 3, 4, 5, 6};
     std::multiset<int> multiset{1, 2, 3, 4, 5, 6};
@@ -57,9 +60,32 @@ TEST(ZipIntegrationTest, ContainersAndAlgorithms)
             auto&& [current_l, current_f] = current;
             auto&& [next_l, next_f] = next;
 
-            std::cout << current_l << ", " << current_f << " vs " << next_l << ", " << next_f << "\n\n";
-
             return current_l + current_f + next_l + next_f == 6;
         });
     EXPECT_EQ(adjacent_iterator, adjacent_zip.begin());
+
+    msd::zip zip2(list, set);
+    auto iter = zip2.begin();
+
+    std::size_t iterations = 0;
+    while (iter != zip2.end()) {  // NOLINT(altera-id-dependent-backward-branch)
+        auto [a, b] = *iter;
+        EXPECT_EQ(a, b);
+        ++iterations;
+        ++iter;
+    }
+    EXPECT_EQ(iterations, 3);
+
+    iterations = 0;
+    for (auto it = zip2.cbegin(); it != zip2.cend(); ++it) {  // NOLINT(altera-id-dependent-backward-branch)
+        ++iterations;
+    }
+    EXPECT_EQ(iterations, 3);
+
+    iterations = 0;
+    // NOLINTNEXTLINE(altera-id-dependent-backward-branch)
+    for (auto it = std::next(zip2.begin()); it != std::prev(zip2.end()); ++it) {
+        ++iterations;
+    }
+    EXPECT_EQ(iterations, 1);
 }