Init commit with a ring buffer

.gitignore

@@ -0,0 +1,7 @@
+# binaries
+test/bin
+
+#eclipse based files
+.cproject
+.project
+.settings/

include/core/core.h

@@ -0,0 +1,48 @@
+/*!
+ * \file core/core.h
+ *
+ * \copyright Copyright (C) 2020-2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_CORE_CORE_H_
+#define TBX_CORE_CORE_H_
+
+//#define __cplusplus 201703L // for developing puproses only
+
+#include <cstddef>
+#include <cstdint>
+
+namespace tbx {
+
+    //! \name size and index
+    //! @{
+    using size_t   = std::size_t;
+    using index_t  = size_t;      //!< index_t and size_t mend to be interchangeable
+
+    using ptrdiff_t= std::ptrdiff_t;
+    //! @}
+}
+
+#endif /* TBX_CORE_CORE_H_ */

include/core/crtp.h

@@ -0,0 +1,55 @@
+/*!
+ * \file core/crtp.h
+ * \brief
+ *      A CRTP idiom helper header
+ *
+ * \copyright Copyright (C) 2020 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_CORE_CRTP_H_
+#define TBX_CORE_CRTP_H_
+
+/*!
+ * \defgroup crtp   CRTP idiom support header
+ *
+ */
+//!@{
+namespace tbx {
+   //! CRTP support tag type
+   struct crtp_tag { };
+   //! virtual support tag type
+   struct virtual_tag { };
+
+   //! \def CRTP boilerplate lines
+   #define _CRTP_IMPL(T) \
+   constexpr T& impl() { return *static_cast<T*>(this); } \
+   constexpr const T& impl() const { return *static_cast<const T*>(this); }
+
+}
+//!@}
+
+
+
+#endif /* TBX_CORE_CRTP_H_ */

include/core/ring_iterator.h

@@ -0,0 +1,227 @@
+/*!
+ * \file cont/ring_iterator.h
+ * \brief
+ *      A ring/circular iterator.
+ *
+ * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ */
+
+#ifndef TBX_CORE_RING_ITERATOR_H_
+#define TBX_CORE_RING_ITERATOR_H_
+
+#include <core/core.h>
+
+#include <iterator>
+#include <type_traits>
+
+namespace tbx {
+
+template<typename Iter_t, size_t N>
+class ring_iterator {
+    //! \name STL iterator traits "forwarding"
+    //! @{
+    protected:
+        using traits_type = std::iterator_traits<Iter_t>;
+
+    public:
+        using iterator_type     = Iter_t;
+        using iterator_category = typename traits_type::iterator_category;
+        using value_type        = typename traits_type::value_type;
+        using difference_type   = typename traits_type::difference_type;
+        using reference         = typename traits_type::reference;
+        using pointer           = typename traits_type::pointer;
+    //! @}
+
+
+    //! \name Constructor / Destructor
+    //! @{
+    public:
+        ring_iterator(const Iter_t base =nullptr) noexcept :
+            base_(base), iter_(base) { }
+
+        ring_iterator(const Iter_t base, size_t elem) noexcept :
+            base_(base), iter_(base + elem) { }
+
+        ring_iterator(const ring_iterator& it) noexcept :
+            base_(it.base_), iter_(it.iter_) { }
+
+        ring_iterator& operator= (const ring_iterator& it) noexcept {
+            base_ = it.base_;
+            iter_ = it.iter_;
+            return *this;
+        }
+    //! @}
+
+    //! \name Forward iterator requirements
+    //! @{
+    public:
+        reference operator*() const noexcept {
+            return *iter_;
+        }
+        pointer operator->() const noexcept {
+            return iter_;
+        }
+        ring_iterator& operator++() noexcept {
+            if (static_cast<size_t>(++iter_ - base_) >= N)
+                iter_ = base_;
+            return *this;
+        }
+        ring_iterator operator++(int) noexcept {
+            ring_iterator it = *this;
+            if (static_cast<size_t>(++iter_ - base_) >= N)
+                iter_ = base_;
+            return it;
+        }
+    //! @}
+
+    //! \name Bidirectional iterator requirements
+    //! @{
+    public:
+        ring_iterator& operator--() noexcept {
+            if (--iter_ < base_)
+                iter_ = base_ + N -1;
+            return *this;
+        }
+        ring_iterator operator--(int) noexcept {
+            ring_iterator it = *this;
+            if (--iter_ < base_)
+                iter_ = base_ + N -1;
+            return it;
+        }
+    //! @}
+
+    //! \name Random access iterator requirements
+    //! @{
+        reference operator[](difference_type n) const noexcept {
+            difference_type k = iter_ - base_;          // ptrdiff from base_
+            return (static_cast<size_t>(k + n) < N) ?
+                base_[k + n] :      // on range
+                base_[k + n - N];   // out of range, loop
+        }
+        ring_iterator& operator+=(difference_type n) noexcept {
+            difference_type k = iter_ - base_;          // ptrdiff from base_
+            iter_ += (static_cast<size_t>(k + n) < N) ?
+                n :                 // on range
+                n - N;              // out of range, loop
+            return *this;
+        }
+        ring_iterator operator+(difference_type n) const noexcept {
+            difference_type k = iter_ - base_;          // ptrdiff from base_
+            return (static_cast<size_t>(k + n) < N) ?
+                ring_iterator(base_, k + n) :           // on range
+                ring_iterator(base_, k + n - N);        // out of range, loop
+        }
+        ring_iterator& operator-=(difference_type n) noexcept {
+            difference_type k = iter_ - base_;          // ptrdiff from base_
+            iter_ -= ((k - n) < 0)?
+                n - N:                                  // out of range, loop
+                n;                                      // on range
+            return *this;
+        }
+        ring_iterator operator-(difference_type n) const noexcept {
+            difference_type k = iter_ - base_;          // ptrdiff from base_
+            return ((k - n) < 0) ?
+                ring_iterator(base_, k - n + N) :       // out of range, loop
+                ring_iterator(base_, k - n);            // on range
+        }
+    //! @}
+
+    //! \name Data members and access
+    //! @{
+        const Iter_t& base() const noexcept {
+            return base_;
+        }
+        const Iter_t& iter() const noexcept {
+            return iter_;
+        }
+        size_t size() noexcept {
+            return N;
+        }
+
+    protected:
+        Iter_t base_;
+        Iter_t iter_;
+    //! @}
+};
+
+// Forward iterator requirements
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator==(const ring_iterator<Iter_L, N>& lhs, const ring_iterator<Iter_R, N>& rhs)
+noexcept {
+    return lhs.iter() == rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator!=(const ring_iterator<Iter_L, N>& lhs, const ring_iterator<Iter_R, N>& rhs)
+noexcept {
+    return lhs.iter() != rhs.iter();
+}
+
+// Random access iterator requirements
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator<(const ring_iterator<Iter_L, N>& lhs, const ring_iterator<Iter_R, N>& rhs)
+noexcept {
+    return lhs.iter() < rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator<=(const ring_iterator<Iter_L, N>& lhs, const ring_iterator<Iter_R, N>& rhs)
+noexcept {
+    return lhs.iter() <= rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator>(const ring_iterator<Iter_L, N>& lhs, const ring_iterator<Iter_R, N>& rhs)
+noexcept {
+    return lhs.iter() > rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline bool operator>=(const ring_iterator<Iter_L, N>& lhs, const ring_iterator<Iter_R, N>& rhs)
+noexcept {
+    return lhs.iter() >= rhs.iter();
+}
+
+template<typename Iter_L, typename Iter_R, size_t N>
+inline auto operator-(const ring_iterator<Iter_L, N>& lhs, const ring_iterator<Iter_R, N>& rhs)
+noexcept
+-> decltype(lhs.iter() - rhs.iter()) {
+    auto diff = lhs.iter() - rhs.iter();
+    return diff < 0 ?
+            diff + N :  // loop
+            diff;       // no loop
+}
+
+template<typename Iter, size_t N>
+inline ring_iterator<Iter, N> operator+(std::ptrdiff_t lhs, const ring_iterator<Iter, N>& rhs)
+noexcept {
+    ring_iterator<Iter, N> it(rhs.iter());
+    return it += lhs;
+}
+
+
+} //namespace tbx;
+
+#endif /* TBX_CORE_RING_ITERATOR_H_ */

test/Makefile

@@ -0,0 +1,243 @@
+#
+# Makefile for tbx unit testing
+#
+# Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
+#
+# The MIT License (MIT)
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+
+#  notes:
+# ==============
+# This makefile provides support for unix-like local builds and
+# docker based builds for gcc and clang.
+# ** msvc is not currently supported.
+#
+# Use cases:
+# 1) build localy using **local rules** in terminal.
+#    example: 
+#       make -j4 MK_ARG="-std=c++14 -fconcepts" build-gcc
+#
+# 2) build localy using **docker based rules** via terminal or script
+#    in order to compile for all compilers/versions/dialects.
+#    example in bash:
+#       #!/bin/bash
+#       for im in gcc:8 gcc:9 gcc:10; do
+#          for dial in -std=c++14 -std=c++17; do
+#             make IMAGE="$im" MK_ARG="$dial" dock-gcc
+#          done
+#       done
+#
+# 3) build inside a docker instance using **local rules** in order to
+#    build and test using a CD/CI system.
+#    example in a yml file:
+#       image: gcc:8
+#       build:
+#          stage: build
+#          - make MK_ARG="-std=c++14" build-gcc
+#          - make MK_ARG="-std=c++14 -fconcepts" build-gcc
+#          - make MK_ARG="-std=c++17" build-gcc
+#          - make MK_ARG="-std=c++17 -fconcepts" build-gcc
+#          - make MK_ARG="-std=c++2a" build-gcc
+#          ... etc
+#       test:
+#          stage: test
+#          - bin/utlTest
+#          ... etc
+
+#
+
+#
+# ============== Project settings ==============
+#
+# note: STM32f101RC/D/E device configuration on SMT32CubeF1 library requires:
+#   1) STM2F101xE pre-define
+#   2) startup_stm32f101xe.s startup file
+#
+
+# Project's name
+PROJECT         := tbx
+# Excecutable's name
+TARGET          := tbxTest
+
+# Source directories list(space seperated). Relative path, under current directory only
+SRC_DIR_LIST    := tests gtest
+
+# Source files list(space seperated).
+SRC_FILES_LIST  := 
+
+# Include directories list(space seperated). Relative path
+INC_DIR_LIST    := ../include gtest
+                   
+# Exclude files list(space seperated). Filenames only.
+# EXC_FILE_LIST := bad.cpp old.cpp
+
+# Build directories
+BUILD_DIR       := bin
+OBJ_DIR         := $(BUILD_DIR)/obj
+DEP_DIR         := $(BUILD_DIR)/.dep
+
+
+# ============== Compiler settings ==============
+CLANGXX         := clang++
+GCCXX           := g++
+CSIZE           := size
+
+ODUMP           := objdump
+OCOPY           := objcopy
+
+# Compiler flags for debug and release
+DEB_CFLAGS      := -std=c++17 -DDEBUG -g3 -Wall -Wextra
+REL_CFLAGS      := -std=c++17 -Wall -Wextra -O2
+# Pre-defines
+# PRE_DEFS := MYCAB=1729 SUPER_MODE
+
+# ============== Linker settings ==============
+# Linker flags
+LDFLAGS         := -pthread
+# Map output file
+MAP_FILE        := output.map
+MAP_FLAG        := -Xlinker -Map=$(BUILD_DIR)/$(MAP_FILE)
+
+# ============== Docker settings ==============
+# We need:
+#  1) Bind the entire project directory(the dir that icludes all the code) as volume.
+#  2) In docker instance change to working directory(where the makefile is). 
+# For utl we use the directories `${PWD%/*}` and `test`.
+# We double-$$ for double evaluating.
+DOCKER_VOL_DIR  := "$${PWD%/*}"
+DOCKER_WRK_DIR  := test
+DOCKER_RUN      := docker run --rm -v $(DOCKER_VOL_DIR):/usr/src/$(PROJECT) -w /usr/src/$(PROJECT)/$(DOCKER_WRK_DIR)
+
+# ============== Default settings ==============
+# compiler and compiler flags. By default docker is not used.
+CFLAGS          := $(DEB_CFLAGS)
+CXX             := $(GCCXX)
+DOCKER          := 
+
+#
+# =========== Main body and Patterns ===========
+#
+ifeq ($(OS), Windows_NT)
+	TARGET := $(TARGET).exe
+endif
+INC     := $(foreach dir,$(INC_DIR_LIST),-I$(dir))
+DEF     := $(foreach def,$(PRE_DEFS),-D$(def))
+EXC     := $(foreach fil,$(EXC_FILE_LIST),                              \
+               $(foreach dir,$(SRC_DIR_LIST),$(wildcard $(dir)/$(fil))) \
+           )
+# source files, object and dependencies list
+# recursive search into current and source directories
+SRC     := $(wildcard *.cpp)
+SRC     += $(foreach dir,$(SRC_DIR_LIST),$(wildcard $(dir)/*.cpp))
+SRC     += $(foreach dir,$(SRC_DIR_LIST),$(wildcard $(dir)/**/*.cpp))
+#SRC     := $(abspath $(filter-out $(EXC),$(SRC)))
+SRC     := $(filter-out $(EXC),$(SRC))
+
+OBJ     := $(foreach file,$(SRC:%.cpp=%.o),$(OBJ_DIR)/$(file))
+DEP     := $(foreach file,$(SRC:%.cpp=%.d),$(DEP_DIR)/$(file))
+
+
+# Make Dependencies pattern.
+# This little trick enables recompilation only when dependencies change
+# and it does so for changes both in source AND header files ;)
+# 
+# It is based on Tom Tromey's method.
+# 
+# Invoke cpp to create makefile rules with dependencies for each source file
+$(DEP_DIR)/%.d: %.cpp
+	@mkdir -p $(@D)
+	@$(DOCKER) $(CXX) -E $(CFLAGS) $(INC) $(DEF) -MM -MT $(OBJ_DIR)/$(<:.cpp=.o) -MF $@ $<
+
+# objects depent on .cpp AND dependency files, which have an empty recipe 
+$(OBJ_DIR)/%.o: %.cpp $(DEP_DIR)/%.d
+	@mkdir -p $(@D)
+	$(DOCKER) $(CXX) -c $(CFLAGS) $(INC) $(DEF) -o $@ $<
+
+# empty recipe for dependency files. This prevents make errors
+$(DEP):
+
+# now include all dependencies
+# After all they are makefile dependency rules ;)
+include $(wildcard $(DEP))
+
+# main target rule
+$(BUILD_DIR)/$(TARGET): $(OBJ)
+	@mkdir -p $(@D)
+	@echo Linking to target: $(TARGET)
+	$(DOCKER) $(CXX) $(LDFLAGS) $(MAP_FLAG) -o $(@D)/$(TARGET) $(OBJ)
+	$(DOCKER) $(ODUMP) -h -S $(BUILD_DIR)/$(TARGET) > $(BUILD_DIR)/$(basename $(TARGET)).list 
+	$(DOCKER) $(OCOPY) -O ihex $(BUILD_DIR)/$(TARGET) $(BUILD_DIR)/$(basename $(TARGET)).hex
+	@echo
+	@echo Print size information
+	@$(CSIZE) $(@D)/$(TARGET)
+	@echo Done
+
+.PHONY: clean
+clean:
+	@echo Cleaning build directories
+	@rm -rf $(OBJ_DIR)
+	@rm -rf $(DEP_DIR)
+	@rm -rf $(BUILD_DIR)
+
+
+#
+# ================ Local build rules =================
+# examples:
+# make MK_ARG="-std=c++14 -fconcepts" build-gcc
+# make MK_ARG="-std=c++17" build-clang
+#
+.PHONY: build-gcc
+build-gcc: CFLAGS += $(MK_ARG)
+build-gcc: $(BUILD_DIR)/$(TARGET)
+
+.PHONY: build-clang
+build-clang: CXX := $(CLANGXX)
+build-clang: CFLAGS += $(MK_ARG)
+build-clang: $(BUILD_DIR)/$(TARGET)
+
+.PHONY: debug
+debug: $(BUILD_DIR)/$(TARGET)
+
+.PHONY: release
+release: CFLAGS := $(REL_FLAGS)
+release: clean $(BUILD_DIR)/$(TARGET)
+
+.PHONY: all
+all: clean release
+
+#
+# ================ Docker based rules ================ 
+# examples:
+# make IMAGE="gcc:8.3" MK_ARG="-std=c++14 -fconcepts" dock-gcc
+# make IMAGE="a-clang-image" MK_ARG="-std=c++17" dock-clang
+#
+.PHONY: dock-gcc
+dock-gcc: DOCKER := $(DOCKER_RUN) $(IMAGE)
+dock-gcc: CFLAGS += $(MK_ARG)
+dock-gcc: $(BUILD_DIR)/$(TARGET)
+
+.PHONY: dock-clang
+dock-clang: CXX := $(CLANGXX)
+dock-clang: DOCKER := $(DOCKER_RUN) $(IMAGE)
+dock-clang: CFLAGS += $(MK_ARG)
+dock-clang: $(BUILD_DIR)/$(TARGET)
+
+

test/main.cpp

@@ -0,0 +1,34 @@
+/*!
+ * \file main.cpp
+ * \brief   Test project main file
+ *
+ * \copyright Copyright (C) 2020-2021 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ *
+ */
+#include <gtest/gtest.h>
+
+GTEST_API_ int main(int argc, char **argv) {
+   testing::InitGoogleTest(&argc, argv);
+   return RUN_ALL_TESTS();
+}
+

test/tests/ring_iterator.cpp

@@ -0,0 +1,231 @@
+/*!
+ * \file ring_iterator.cpp
+ * \brief
+ *      Unit tests for ring_iterator
+ *
+ * \copyright Copyright (C) 2020 Christos Choutouridis <christos@choutouridis.net>
+ *
+ * <dl class=\"section copyright\"><dt>License</dt><dd>
+ * The MIT License (MIT)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ * </dd></dl>
+ *
+ */
+#include <core/ring_iterator.h>
+#include <gtest/gtest.h>
+
+#include <array>
+#include <type_traits>
+
+namespace Tring_iterator {
+    using namespace tbx;
+
+    // Test construction
+    TEST(Tring_iterator, construct) {
+        int A[10];
+
+        //default constructor
+        ring_iterator<int*, 10> i1;
+        EXPECT_EQ(nullptr, i1.base());
+        EXPECT_EQ(nullptr, i1.iter());
+        EXPECT_EQ(10UL, i1.size());
+
+        // implementation specific (you can remove it freely)
+        EXPECT_EQ(2*sizeof(int*), sizeof(i1));
+
+        // basic
+        ring_iterator<int*, 10> i2(A);
+        EXPECT_EQ(A, i2.base());
+        EXPECT_EQ(A, i2.iter());
+        EXPECT_EQ(10UL, i2.size());
+
+        // basic from assignment
+        ring_iterator<int*, 10> i3 = A;
+        EXPECT_EQ(A, i3.base());
+        EXPECT_EQ(A, i3.iter());
+        EXPECT_EQ(10UL, i3.size());
+
+        // basic with offset
+        ring_iterator<int*, 10> i4(A, 5);
+        EXPECT_EQ(A, i4.base());
+        EXPECT_EQ(&A[5], i4.iter());
+        EXPECT_EQ(10UL, i4.size());
+
+        // copy (Legacy iterator)
+        auto i5 = i2;
+        EXPECT_EQ(A, i5.base());
+        EXPECT_EQ(A, i5.iter());
+        EXPECT_EQ(10UL, i5.size());
+
+        // arbitrary type
+        struct TT { int a,b,c; };
+        std::array<TT, 10> t;
+        ring_iterator<TT*, 10> it(t.data(), 2);
+        EXPECT_EQ(t.begin(), it.base());
+        EXPECT_EQ(&t[2], it.iter());
+        EXPECT_EQ(10UL, it.size());
+    }
+
+    // Legacy iterator
+    TEST(Tring_iterator, LegacyIterator) {
+
+        EXPECT_EQ(true, (std::is_same<int, typename ring_iterator<int*, 10>::value_type>::value));
+        EXPECT_EQ(true, (std::is_same<std::ptrdiff_t, typename ring_iterator<int*, 10>::difference_type>::value));
+        EXPECT_EQ(true, (std::is_same<int&, typename ring_iterator<int*, 10>::reference>::value));
+        EXPECT_EQ(true, (std::is_same<int*, typename ring_iterator<int*, 10>::pointer>::value));
+        EXPECT_EQ(true, (std::is_same<std::random_access_iterator_tag, typename ring_iterator<int*, 10>::iterator_category>::value));
+
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10> i1(A);
+
+        // copy constructible/assignable
+        auto i2 = i1;
+        EXPECT_EQ(A, i2.base());
+        EXPECT_EQ(A, i2.iter());
+        EXPECT_EQ(10UL, i2.size());
+
+        // dereferenceable - incrementable
+        ring_iterator<int*, 10> i3(A);
+        EXPECT_EQ(true, (std::is_reference<decltype(*i3)>::value));
+        EXPECT_EQ(true, (std::is_same<ring_iterator<int*, 10>&, decltype(++i3)>::value));
+        EXPECT_EQ(true, (std::is_reference<decltype((*i3++))>::value));
+
+        // more practical
+        ring_iterator<int*, 10> i4(A);
+        ring_iterator<int*, 10> i5(A, 9);
+        EXPECT_EQ(A[0], *i4);
+        EXPECT_EQ(&A[1], (++i4).iter());
+        // check loop
+        EXPECT_EQ(A[9], *i5);
+        EXPECT_EQ(&A[0], (++i5).iter());
+    }
+
+    // Legacy input iterator
+    TEST(Tring_iterator, LegacyInputIterator) {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10> i1(A), i2(A), i3(A, 1);
+
+        struct T { int m; };
+        T B[5] { {0}, {1}, {2}, {3}, {4}};
+        ring_iterator<T*, 5> it(B);
+
+        EXPECT_EQ (true, (std::is_same<bool, decltype(i1 == i2)>::value));
+        EXPECT_EQ (true, (std::is_same<bool, decltype(i1 != i2)>::value));
+        EXPECT_EQ (true, (std::is_same<int&, decltype(*i1)>::value));
+        EXPECT_EQ (true, (std::is_same<int, decltype(it->m)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10>&, decltype(++i1)>::value));
+        EXPECT_EQ (true, (std::is_same<int&, decltype(*i1++)>::value));
+
+        // more practical
+        EXPECT_EQ (true, i1 == i2);
+        EXPECT_EQ (true, i1 != i3);
+        EXPECT_EQ (0, *i1);
+        EXPECT_EQ (0, it->m);
+        EXPECT_EQ (true, (++i1 == i3));
+        EXPECT_EQ (1, *i1++);
+        EXPECT_EQ (2, *i1);
+    }
+
+    // Legacy input iterator
+    TEST(Tring_iterator, LegacyOutputIterator) {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10> it(A);
+
+        EXPECT_EQ (true, (std::is_assignable<decltype(*it), int>::value));
+        EXPECT_EQ (true, (std::is_assignable<decltype(*it++), int>::value));
+
+        // more practical
+        *it = 42;
+        EXPECT_EQ (42, A[0]);
+        *it++ = 7;
+        EXPECT_EQ (7, A[0]);
+        EXPECT_EQ (&A[1], it.iter());
+    }
+
+    // Legacy forward iterator
+    TEST(Tring_iterator, LegacyForwardIterator)
+     {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10> it(A);
+
+        EXPECT_EQ (0, *it++);
+        EXPECT_EQ (1, *it);
+    }
+
+    // Legacy bidirectional iterator
+    TEST(Tring_iterator, LegacyBidirectionalIterator) {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10> it(A);
+
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10>&, decltype(--it)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10>, decltype(it--)>::value));
+        EXPECT_EQ (true, (std::is_same<int&, decltype(*it--)>::value));
+
+        // more practical
+        ring_iterator<int*, 10> i1(A), i2(A, 9);
+        EXPECT_EQ (9, *i2--);   // check loop also
+        EXPECT_EQ (8, *i2);
+        EXPECT_EQ (0, *i1--);   // check loop also
+        EXPECT_EQ (9, *i1);
+    }
+
+    // Legacy random access iterator
+    TEST(Tring_iterator, LegacyRandomAccessIterator) {
+        int A[10] {0, 1, 2, 3, 4, 5, 6, 7, 8 , 9};
+        ring_iterator<int*, 10> it1(A), it2(A, 7);
+
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10>&, decltype(it1 += 7)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10>, decltype(it1 + 7)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10>, decltype(7 + it1)>::value));
+
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10>&, decltype(it1 -= 7)>::value));
+        EXPECT_EQ (true, (std::is_same<ring_iterator<int*, 10>, decltype(it1 - 7)>::value));
+
+        EXPECT_EQ (true, (std::is_same<std::ptrdiff_t, decltype(it1 - it2)>::value));
+        EXPECT_EQ (true, (std::is_same<int&, decltype(it1[7])>::value));
+
+        EXPECT_EQ (true, (std::is_same<bool, decltype(it1 < it2)>::value));
+        EXPECT_EQ (true, (std::is_same<bool, decltype(it1 > it2)>::value));
+        EXPECT_EQ (true, (std::is_same<bool, decltype(it1 <= it2)>::value));
+        EXPECT_EQ (true, (std::is_same<bool, decltype(it1 >= it2)>::value));
+
+        // more practical
+        ring_iterator<int*, 10> i1(A), i2(A);
+        i1 += 7;
+        EXPECT_EQ (7, *i1);
+        i1 -= 7;
+        EXPECT_EQ (0, *i1);
+        i1 += 11;
+        EXPECT_EQ (1, *i1);
+        i1 -= 2;
+        EXPECT_EQ (9, *i1);
+
+        EXPECT_EQ (7, *(i2+7));
+        EXPECT_EQ (7, *(7+i2));
+        EXPECT_EQ (1, *(i2+11));
+        EXPECT_EQ (1, *(11+i2));
+        EXPECT_EQ (7, *(i1-2));
+        EXPECT_EQ (8, *(i2-2));
+
+        EXPECT_EQ (9, (i1 - i2));
+        EXPECT_EQ (1, (i2 - i1));   // loop
+
+    }
+}