FrancoisCarouge · FrancoisCarouge · Jul 28, 2022 · Jul 11, 2022
diff --git a/.clang-tidy b/.clang-tidy
@@ -2,6 +2,7 @@ Checks: '*,
         -altera-struct-pack-align,
         -fuchsia-overloaded-operator,
         -fuchsia-trailing-return,
+        -llvmlibc-callee-namespace,
         -llvmlibc-implementation-in-namespace,
         -llvmlibc-restrict-system-libc-headers,
         -portability-simd-intrinsics,

diff --git a/.github/workflows/deploy_test_coverage_coveralls.yml b/.github/workflows/deploy_test_coverage_coveralls.yml
@@ -17,16 +17,27 @@ jobs:
     - name: Install
       run: |
         sudo apt install gcc-11 g++-11 lcov
-        ( cd /tmp ; mkdir eigen ;
+        ( cd /tmp ;
           git clone --depth 1 https://gitlab.com/libeigen/eigen.git ;
           ( cd eigen ;
-            mkdir build ) ;
-          ( cd eigen/build ; 
-            cmake .. ; 
-            cmake --build . ;
-            sudo make install ) )
+            mkdir build ;
+            ( cd build ; 
+              cmake .. ; 
+              cmake --build . ;
+              sudo make install ; ) ) )
+        ( cd /tmp ;
+          git clone --depth 1 https://github.com/fmtlib/fmt.git ;
+          ( cd fmt ;
+            mkdir build ;
+            ( cd build ;
+              cmake .. ;
+              sudo make install ; ) ) )
     - name: Build
-      run: gcc-11 sample/*.cpp source/*.cpp test/*.cpp -Iinclude -I/usr/local/include/eigen3 -O0 -g -std=c++23 -fmodules-ts --coverage -fno-inline -lstdc++ -lm
+      run: |
+        gcc-11 \
+          sample/*.cpp source/*.cpp test/*.cpp \
+          -Iinclude -I/usr/local/include/eigen3 -Isupport/include/fcarouge \
+          -O0 -g -std=c++23 -fmodules-ts --coverage -fno-inline -lstdc++ -lm -lfmt
     - name: "Coverage: Base"
       run: |
         lcov --rc lcov_branch_coverage=1 --gcov-tool gcov-11 --capture --initial --directory . --output-file base.info

diff --git a/.github/workflows/verify_code_static_analysis_tidy.yml b/.github/workflows/verify_code_static_analysis_tidy.yml
@@ -17,17 +17,27 @@ jobs:
     - name: Install
       run: |
         sudo apt install clang-tidy-14
-        ( cd /tmp ; mkdir eigen ;
+        ( cd /tmp ;
           git clone --depth 1 https://gitlab.com/libeigen/eigen.git ;
           ( cd eigen ;
-            mkdir build ) ;
-          ( cd eigen/build ; 
-            cmake .. ; 
-            cmake --build . ;
-            sudo make install ) )
+            mkdir build ;
+            ( cd build ; 
+              cmake .. ; 
+              cmake --build . ;
+              sudo make install ; ) ) )
+        ( cd /tmp ;
+          git clone --depth 1 https://github.com/fmtlib/fmt.git ;
+          ( cd fmt ;
+            mkdir build ;
+            ( cd build ;
+              CXX=clang++-14 cmake -DFMT_HEADER_ONLY=TRUE .. ;
+              sudo make install ; ) ) )
     - name: Tidy
       run: |
         FILES=`find . -iname *.hpp`
         clang-tidy-14 ${FILES} \
           --warnings-as-errors=* \
-          -- -x c++ -Wall -Wextra -pedantic -std=c++2b -Iinclude -I/usr/local/include/eigen3
+          -- -x c++ \
+            -Iinclude -I/usr/local/include/eigen3 -Isupport/include/fcarouge \
+            -DFMT_HEADER_ONLY \
+            -Wall -Wextra -pedantic -std=c++2b -stdlib=libc++ -lfmt
diff --git a/.github/workflows/verify_test_memory_valgrind.yml b/.github/workflows/verify_test_memory_valgrind.yml
@@ -17,15 +17,26 @@ jobs:
     - name: Install
       run: |
         sudo apt install gcc-11 g++-11 valgrind
-        ( cd /tmp ; mkdir eigen ;
+        ( cd /tmp ;
           git clone --depth 1 https://gitlab.com/libeigen/eigen.git ;
           ( cd eigen ;
-            mkdir build ) ;
-          ( cd eigen/build ; 
-            cmake .. ; 
-            cmake --build . ;
-            sudo make install ) )
+            mkdir build ;
+            ( cd build ; 
+              cmake .. ; 
+              cmake --build . ;
+              sudo make install ; ) ) )
+        ( cd /tmp ;
+          git clone --depth 1 https://github.com/fmtlib/fmt.git ;
+          ( cd fmt ;
+            mkdir build ;
+            ( cd build ;
+              cmake .. ;
+              sudo make install ; ) ) )
     - name: Build
-      run: gcc-11 sample/*.cpp test/*.cpp source/*.cpp -Iinclude -I/usr/local/include/eigen3 -g -O0 -std=c++23 -lstdc++ -lm
+      run: |
+        gcc-11 \
+          sample/*.cpp test/*.cpp source/*.cpp \
+          -Iinclude -I/usr/local/include/eigen3 -Isupport/include/fcarouge \
+          -g -O0 -std=c++23 -lstdc++ -lm -lfmt
     - name: Test
       run: valgrind --verbose ./a.out
diff --git a/.github/workflows/verify_test_sanitizer_address.yml b/.github/workflows/verify_test_sanitizer_address.yml
@@ -17,15 +17,26 @@ jobs:
     - name: Install
       run: |
         sudo apt install gcc-11 g++-11
-        ( cd /tmp ; mkdir eigen ;
+        ( cd /tmp ;
           git clone --depth 1 https://gitlab.com/libeigen/eigen.git ;
           ( cd eigen ;
-            mkdir build ) ;
-          ( cd eigen/build ; 
-            cmake .. ; 
-            cmake --build . ;
-            sudo make install ) )
+            mkdir build ;
+            ( cd build ; 
+              cmake .. ; 
+              cmake --build . ;
+              sudo make install ; ) ) )
+        ( cd /tmp ;
+          git clone --depth 1 https://github.com/fmtlib/fmt.git ;
+          ( cd fmt ;
+            mkdir build ;
+            ( cd build ;
+              cmake .. ;
+              sudo make install ; ) ) )
     - name: Build
-      run: gcc-11 sample/*.cpp test/*.cpp source/*.cpp -Iinclude -I/usr/local/include/eigen3 -std=c++23 -g -fsanitize=address -fsanitize-address-use-after-scope -fno-omit-frame-pointer -lstdc++ -lm
+      run: |
+        gcc-11 \
+          sample/*.cpp test/*.cpp source/*.cpp \
+          -Iinclude -I/usr/local/include/eigen3 -Isupport/include/fcarouge \
+          -std=c++23 -g -fsanitize=address -fsanitize-address-use-after-scope -fno-omit-frame-pointer -lstdc++ -lm -lfmt
     - name: Test
       run: ASAN_OPTIONS=verbosity=2:strict_string_checks=1:detect_stack_use_after_return=1:check_initialization_order=1:strict_init_order=1 ./a.out
diff --git a/.github/workflows/verify_test_sanitizer_leak.yml b/.github/workflows/verify_test_sanitizer_leak.yml
@@ -17,15 +17,26 @@ jobs:
     - name: Install
       run: |
         sudo apt install gcc-11 g++-11
-        ( cd /tmp ; mkdir eigen ;
+        ( cd /tmp ;
           git clone --depth 1 https://gitlab.com/libeigen/eigen.git ;
           ( cd eigen ;
-            mkdir build ) ;
-          ( cd eigen/build ; 
-            cmake .. ; 
-            cmake --build . ;
-            sudo make install ) )
+            mkdir build ;
+            ( cd build ; 
+              cmake .. ; 
+              cmake --build . ;
+              sudo make install ; ) ) )
+        ( cd /tmp ;
+          git clone --depth 1 https://github.com/fmtlib/fmt.git ;
+          ( cd fmt ;
+            mkdir build ;
+            ( cd build ;
+              cmake .. ;
+              sudo make install ; ) ) )
     - name: Build
-      run: gcc-11 sample/*.cpp test/*.cpp source/*.cpp -Iinclude -I/usr/local/include/eigen3 -std=c++23 -g -fsanitize=leak -lstdc++ -lm
+      run: |
+        gcc-11 \
+          sample/*.cpp test/*.cpp source/*.cpp \
+          -Iinclude -I/usr/local/include/eigen3 -Isupport/include/fcarouge \
+          -std=c++23 -g -fsanitize=leak -lstdc++ -lm -lfmt
     - name: Test
       run: LSAN_OPTIONS=verbosity=2 ./a.out
diff --git a/.github/workflows/verify_test_sanitizer_thread.yml b/.github/workflows/verify_test_sanitizer_thread.yml
@@ -17,15 +17,26 @@ jobs:
     - name: Install
       run: |
         sudo apt install gcc-11 g++-11
-        ( cd /tmp ; mkdir eigen ;
+        ( cd /tmp ;
           git clone --depth 1 https://gitlab.com/libeigen/eigen.git ;
           ( cd eigen ;
-            mkdir build ) ;
-          ( cd eigen/build ; 
-            cmake .. ; 
-            cmake --build . ;
-            sudo make install ) )
+            mkdir build ;
+            ( cd build ; 
+              cmake .. ; 
+              cmake --build . ;
+              sudo make install ; ) ) )
+        ( cd /tmp ;
+          git clone --depth 1 https://github.com/fmtlib/fmt.git ;
+          ( cd fmt ;
+            mkdir build ;
+            ( cd build ;
+              cmake .. ;
+              sudo make install ; ) ) )
     - name: Build
-      run: gcc-11 sample/*.cpp test/*.cpp source/*.cpp -Iinclude -I/usr/local/include/eigen3 -std=c++23 -g -fsanitize=thread -lstdc++ -lm
+      run: |
+        gcc-11 \
+          sample/*.cpp test/*.cpp source/*.cpp \
+          -Iinclude -I/usr/local/include/eigen3 -Isupport/include/fcarouge \
+          -std=c++23 -g -fsanitize=thread -lstdc++ -lm -lfmt
     - name: Test
       run: TSAN_OPTIONS=verbosity=2 ./a.out
diff --git a/.github/workflows/verify_test_sanitizer_undefined_behavior.yml b/.github/workflows/verify_test_sanitizer_undefined_behavior.yml
@@ -17,15 +17,26 @@ jobs:
     - name: Install
       run: |
         sudo apt install gcc-11 g++-11
-        ( cd /tmp ; mkdir eigen ;
+        ( cd /tmp ;
           git clone --depth 1 https://gitlab.com/libeigen/eigen.git ;
           ( cd eigen ;
-            mkdir build ) ;
-          ( cd eigen/build ; 
-            cmake .. ; 
-            cmake --build . ;
-            sudo make install ) )
+            mkdir build ;
+            ( cd build ; 
+              cmake .. ; 
+              cmake --build . ;
+              sudo make install ; ) ) )
+        ( cd /tmp ;
+          git clone --depth 1 https://github.com/fmtlib/fmt.git ;
+          ( cd fmt ;
+            mkdir build ;
+            ( cd build ;
+              cmake .. ;
+              sudo make install ; ) ) )
     - name: Build
-      run: gcc-11 sample/*.cpp test/*.cpp source/*.cpp -Iinclude -I/usr/local/include/eigen3 -std=c++23 -g -fsanitize=undefined -lstdc++ -lm
+      run: |
+        gcc-11 \
+          sample/*.cpp test/*.cpp source/*.cpp \
+          -Iinclude -I/usr/local/include/eigen3 -Isupport/include/fcarouge \
+          -std=c++23 -g -fsanitize=undefined -lstdc++ -lm -lfmt
     - name: Test
       run: UBSAN_OPTIONS=verbosity=2 ./a.out
diff --git a/.github/workflows/verify_test_ubuntu-22-04_clang-trunk.yml b/.github/workflows/verify_test_ubuntu-22-04_clang-trunk.yml
@@ -20,15 +20,27 @@ jobs:
     - name: Install
       run: |
         sudo apt install clang-14 lld-14 libc++-14-dev libc++abi-14-dev
-        ( cd /tmp ; mkdir eigen ;
+        ( cd /tmp ;
           git clone --depth 1 https://gitlab.com/libeigen/eigen.git ;
           ( cd eigen ;
-            mkdir build ) ;
-          ( cd eigen/build ; 
-            cmake .. ; 
-            cmake --build . ;
-            sudo make install ) )
+            mkdir build ;
+            ( cd build ; 
+              cmake .. ; 
+              cmake --build . ;
+              sudo make install ; ) ) )
+        ( cd /tmp ;
+          git clone --depth 1 https://github.com/fmtlib/fmt.git ;
+          ( cd fmt ;
+            mkdir build ;
+            ( cd build ;
+              CXX=clang++-14 cmake -DFMT_HEADER_ONLY=TRUE .. ;
+              sudo make install ; ) ) )
     - name: Build
-      run: clang++-14 sample/*.cpp source/*.cpp test/*.cpp -Iinclude -I/usr/local/include/eigen3 -Wall -Wextra -pedantic -std=c++2b -stdlib=libc++
+      run: |
+        clang++-14 \
+          sample/*.cpp source/*.cpp test/*.cpp \
+          -Iinclude -I/usr/local/include/eigen3 -Isupport/include/fcarouge \
+          -DFMT_HEADER_ONLY \
+          -Wall -Wextra -pedantic -std=c++2b -stdlib=libc++ -lfmt
     - name: Run
       run: ./a.out
diff --git a/.github/workflows/verify_test_ubuntu-22-04_gcc-trunk.yml b/.github/workflows/verify_test_ubuntu-22-04_gcc-trunk.yml
@@ -16,15 +16,27 @@ jobs:
       run: |
         wget http://kayari.org/gcc-latest/gcc-latest.deb
         sudo dpkg -i gcc-latest.deb
-        ( cd /tmp ; mkdir eigen ;
+        ( cd /tmp ;
           git clone --depth 1 https://gitlab.com/libeigen/eigen.git ;
           ( cd eigen ;
-            mkdir build ) ;
-          ( cd eigen/build ; 
-            cmake .. ; 
-            cmake --build . ;
-            sudo make install ) )
+            mkdir build ;
+            ( cd build ; 
+              cmake .. ; 
+              cmake --build . ;
+              sudo make install ; ) ) )
+        ( cd /tmp ;
+          git clone --depth 1 https://github.com/fmtlib/fmt.git ;
+          ( cd fmt ;
+            mkdir build ;
+            ( cd build ;
+              cmake .. ;
+              sudo make install ; ) ) )
     - name: Build
-      run: LD_LIBRARY_PATH=/opt/gcc-latest/lib64 LD_RUN_PATH=/opt/gcc-latest/lib64 /opt/gcc-latest/bin/gcc sample/*.cpp test/*.cpp source/*.cpp -Iinclude -I/usr/local/include/eigen3 -Wall -Wextra -pedantic -std=c++23 -lstdc++ -lm
+      run: |
+        LD_LIBRARY_PATH=/opt/gcc-latest/lib64 LD_RUN_PATH=/opt/gcc-latest/lib64 \
+        /opt/gcc-latest/bin/gcc \
+          sample/*.cpp test/*.cpp source/*.cpp \
+          -Iinclude -I/usr/local/include/eigen3 -Isupport/include/fcarouge \
+          -Wall -Wextra -pedantic -std=c++23 -lstdc++ -lm -lfmt
     - name: Run
       run: ./a.out
diff --git a/README.md b/README.md
@@ -18,6 +18,7 @@ The library supports simple and extended filters. The update equation uses the J
   - [Member Functions](#member-functions)
     - [Characteristics](#characteristics)
     - [Modifiers](#modifiers)
+- [Format](#format)
 - [Resources](#resources)
 - [License](#license)
 
@@ -260,6 +261,17 @@ class kalman
 | `update` | Updates the estimates with the outcome of a measurement. |
 | `predict` | Produces estimates of the state variables and uncertainties. |
 
+# Format
+
+A specialization of the standard formatter is provided for the filter. Use `std::format` to store a formatted representation of all of the characteristics of the filter in a new string. Standard format parameters to be supported.
+
+```cpp
+fcarouge::kalman k;
+
+std::string message{ std::format("{}", k) };
+// {f:1,h:1,k:1,p:1,q:0,r:0,s:1,x:0,y:0,z:0}
+```
+
 # Resources
 
 Awesome resources to learn about Kalman filters:

diff --git a/include/fcarouge/internal/format.hpp b/include/fcarouge/internal/format.hpp
@@ -39,4 +39,45 @@ For more information, please refer to <https://unlicense.org> */
 #ifndef FCAROUGE_INTERNAL_FORMAT_HPP
 #define FCAROUGE_INTERNAL_FORMAT_HPP
 
+#include <format>
+
+namespace fcarouge
+{
+template <typename State, typename Output, typename Input, typename Transpose,
+          typename Symmetrize, typename Divide, typename Identity,
+          typename UpdateTypes, typename PredictionTypes>
+class kalman;
+} // namespace fcarouge
+
+template <typename State, typename Output, typename Input, typename Transpose,
+          typename Symmetrize, typename Divide, typename Identity,
+          typename UpdateTypes, typename PredictionTypes, typename Char>
+struct std::formatter<
+    fcarouge::kalman<State, Output, Input, Transpose, Symmetrize, Divide,
+                     Identity, UpdateTypes, PredictionTypes>,
+    Char> {
+  //! @todo Support parsing arguments.
+  constexpr auto parse(std::basic_format_parse_context<Char> &parse_context)
+  {
+    return parse_context.begin();
+  }
+
+  // @todo How to support different nested types?
+  template <typename OutputIt>
+  auto format(const fcarouge::kalman<State, Output, Input, Transpose,
+                                     Symmetrize, Divide, Identity, UpdateTypes,
+                                     PredictionTypes> &filter,
+              std::basic_format_context<OutputIt, Char> &format_context)
+      -> OutputIt
+  {
+    return format_to(
+        format_context.out(),
+        "{{f:{},g:{},h:{},k:{},p:{},q:{},r:{},s:{},u:{},x:{},y:{},z:{}}}",
+        filter.f(), filter.g(), filter.h(), filter.k(), filter.p(), filter.q(),
+        filter.r(), filter.s(), filter.u(), filter.x(), filter.y(), filter.z());
+  }
+
+  //! @}
+};
+
 #endif // FCAROUGE_INTERNAL_FORMAT_HPP