feat: Formatting support for Kalman related types added

example/kalman_filter/kalman.h

@@ -151,26 +151,53 @@ constexpr Q covariance_extrapolation(Q uncertainty, Q process_noise_variance)
 }  // namespace kalman
 
 template<typename... Qs>
-struct fmt::formatter<kalman::state<Qs...>> : formatter<std::string> {
+struct fmt::formatter<kalman::state<Qs...>> {
+  constexpr auto parse(format_parse_context& ctx)
+  {
+    detail::dynamic_specs_handler<format_parse_context> handler(specs, ctx);
+    return detail::parse_format_specs(ctx.begin(), ctx.end(), handler);
+  }
+
   template<typename FormatContext>
   auto format(const kalman::state<Qs...>& s, FormatContext& ctx)
   {
-    std::string txt = [&]{
+    memory_buffer value_buffer;
+    auto to_value_buffer = std::back_inserter(value_buffer);
+    if (specs.precision != -1) {
       if constexpr(sizeof...(Qs) == 1)
-        return fmt::format("{1:%.{0}Q %q}", precision, kalman::get<0>(s));
+        format_to(to_value_buffer, "{1:%.{0}Q %q}", specs.precision, kalman::get<0>(s));
       else if constexpr(sizeof...(Qs) == 2)
-        return fmt::format("{{ {1:%.{0}Q %q}, {2:%.{0}Q %q} }}", precision, kalman::get<0>(s), kalman::get<1>(s));
+        format_to(to_value_buffer, "{{ {1:%.{0}Q %q}, {2:%.{0}Q %q} }}", specs.precision, kalman::get<0>(s), kalman::get<1>(s));
       else
-        return fmt::format("{{ {1:%.{0}Q %q}, {2:%.{0}Q %q}, {3:%.{0}Q %q} }}", precision, kalman::get<0>(s), kalman::get<1>(s), kalman::get<2>(s));
+        format_to(to_value_buffer, "{{ {1:%.{0}Q %q}, {2:%.{0}Q %q}, {3:%.{0}Q %q} }}", specs.precision, kalman::get<0>(s), kalman::get<1>(s), kalman::get<2>(s));
-    }();
+    }
-    return formatter<std::string>::format(txt, ctx);
+    else {
+      if constexpr(sizeof...(Qs) == 1)
+        format_to(to_value_buffer, "{}", kalman::get<0>(s));
+      else if constexpr(sizeof...(Qs) == 2)
+        format_to(to_value_buffer, "{{ {}, {} }}", kalman::get<0>(s), kalman::get<1>(s));
+      else
+        format_to(to_value_buffer, "{{ {}, {}, {} }}", kalman::get<0>(s), kalman::get<1>(s), kalman::get<2>(s));
+    }
+
+    basic_memory_buffer<char> global_format_buffer;
+    units::detail::global_format_specs<char> global_specs = { specs.fill, specs.align, specs.width };
+    units::detail::format_global_buffer(std::back_inserter(global_format_buffer), global_specs);
+
+    return format_to(ctx.out(), to_string(global_format_buffer), to_string(value_buffer));
   }
 private:
-  int precision = 1;  // TODO find the easiest way to parse it from context
+  detail::dynamic_format_specs<char> specs;
 };
 
 template<typename Q>
-struct fmt::formatter<kalman::estimation<Q>> : formatter<std::string> {
+struct fmt::formatter<kalman::estimation<Q>> {
+  constexpr auto parse(format_parse_context& ctx)
+  {
+    detail::dynamic_specs_handler<format_parse_context> handler(specs, ctx);
+    return detail::parse_format_specs(ctx.begin(), ctx.end(), handler);
+  }
+
   template<typename FormatContext>
   auto format(kalman::estimation<Q> e, FormatContext& ctx)
   {
@@ -180,9 +207,22 @@ struct fmt::formatter<kalman::estimation<Q>> : formatter<std::string> {
       else
         return t.relative();
     }(kalman::get<0>(e.state));
-    std::string txt = fmt::format("{0:%.{2}Q} ± {1:%.{2}Q} {0:%q}", q, sqrt(e.uncertainty), precision);
+
-    return formatter<std::string>::format(txt, ctx);
+    memory_buffer value_buffer;
+    auto to_value_buffer = std::back_inserter(value_buffer);
+    if (specs.precision != -1) {
+      format_to(to_value_buffer, "{0:%.{2}Q} ± {1:%.{2}Q} {0:%q}", q, sqrt(e.uncertainty), specs.precision);
+    }
+    else {
+      format_to(to_value_buffer, "{0:%Q} ± {1:%Q} {0:%q}", q, sqrt(e.uncertainty));
+    }
+
+    basic_memory_buffer<char> global_format_buffer;
+    units::detail::global_format_specs<char> global_specs = { specs.fill, specs.align, specs.width };
+    units::detail::format_global_buffer(std::back_inserter(global_format_buffer), global_specs);
+
+    return format_to(ctx.out(), to_string(global_format_buffer), to_string(value_buffer));
   }
 private:
-  int precision = 3;  // TODO find the easiest way to parse it from context
+  detail::dynamic_format_specs<char> specs;
 };

example/kalman_filter/kalman_filter-example_2.cpp

@@ -40,7 +40,7 @@ void print_header(const kalman::State auto& initial)
 
 void print(auto iteration, Quantity auto measured, const kalman::State auto& current, const kalman::State auto& next)
 {
-  fmt::print("{:2} | {:8} | {} | {}\n", iteration, measured, current, next);
+  fmt::print("{:2} | {:8} | {:.1} | {:.1}\n", iteration, measured, current, next);
 }
 
 int main()

example/kalman_filter/kalman_filter-example_3.cpp

@@ -35,12 +35,12 @@ using namespace units;
 void print_header(const kalman::State auto& initial)
 {
   fmt::print("Initial: {}\n", initial);
-  fmt::print("{:>2} | {:>8} | {:>23} | {:>23}\n", "N", "Measured", "Curr. Estimate", "Next Estimate");
+  fmt::print("{:>2} | {:>8} | {:>24} | {:>24}\n", "N", "Measured", "Curr. Estimate", "Next Estimate");
 }
 
 void print(auto iteration, Quantity auto measured, const kalman::State auto& current, const kalman::State auto& next)
 {
-  fmt::print("{:2} | {:8} | {} | {}\n", iteration, measured, current, next);
+  fmt::print("{:2} | {:8} | {:>24.1} | {:>24.1}\n", iteration, measured, current, next);
 }
 
 int main()

example/kalman_filter/kalman_filter-example_4.cpp

@@ -41,7 +41,7 @@ void print_header(const kalman::State auto& initial)
 
 void print(auto iteration, Quantity auto measured, const kalman::State auto& current, const kalman::State auto& next)
 {
-  fmt::print("{:2} | {:8} | {:>35} | {:>35}\n", iteration, measured, current, next);
+  fmt::print("{:2} | {:8} | {:>35.1} | {:>35.1}\n", iteration, measured, current, next);
 }
 
 int main()

example/kalman_filter/kalman_filter-example_5.cpp

@@ -40,7 +40,7 @@ void print_header(kalman::estimation<Q> initial)
 template<Quantity Q, Dimensionless K>
 void print(auto iteration, K gain, Q measured, kalman::estimation<Q> current, kalman::estimation<Q> next)
 {
-  fmt::print("{:2} | {:5%.2Q} | {:8} | {:16} | {:16}\n", iteration, gain, measured, current, next);
+  fmt::print("{:2} | {:5%.2Q} | {:8} | {:>16.2} | {:>16.2}\n", iteration, gain, measured, current, next);
 }
 
 int main()

example/kalman_filter/kalman_filter-example_6.cpp

@@ -61,7 +61,7 @@ void print_header(kalman::estimation<QP> initial)
 template<QuantityPoint QP, Dimensionless K>
 void print(auto iteration, K gain, QP measured, kalman::estimation<QP> current, kalman::estimation<QP> next)
 {
-  fmt::print("{:2} | {:7%.4Q} | {:10%.3Q %q} | {:>18} | {:>18}\n", iteration, gain, measured.relative(), current, next);
+  fmt::print("{:2} | {:7%.4Q} | {:10%.3Q %q} | {:>18.3} | {:>18.3}\n", iteration, gain, measured.relative(), current, next);
 }
 
 int main()

example/kalman_filter/kalman_filter-example_7.cpp

@@ -61,7 +61,7 @@ void print_header(kalman::estimation<QP> initial)
 template<QuantityPoint QP, Dimensionless K>
 void print(auto iteration, K gain, QP measured, kalman::estimation<QP> current, kalman::estimation<QP> next)
 {
-  fmt::print("{:2} | {:7%.4Q} | {:10%.3Q %q} | {:>18} | {:>18}\n", iteration, gain, measured.relative(), current, next);
+  fmt::print("{:2} | {:7%.4Q} | {:10%.3Q %q} | {:>18.3} | {:>18.3}\n", iteration, gain, measured.relative(), current, next);
 }
 
 int main()

example/kalman_filter/kalman_filter-example_8.cpp

@@ -55,13 +55,13 @@ template<QuantityPoint QP>
 void print_header(kalman::estimation<QP> initial)
 {
   fmt::print("Initial: {}\n", initial);
-  fmt::print("{:>2} | {:>7} | {:>10} | {:>18} | {:>18}\n", "N", "Gain", "Measured", "Curr. Estimate", "Next Estimate");
+  fmt::print("{:>2} | {:>7} | {:>10} | {:>16} | {:>16}\n", "N", "Gain", "Measured", "Curr. Estimate", "Next Estimate");
 }
 
 template<QuantityPoint QP, Dimensionless K>
 void print(auto iteration, K gain, QP measured, kalman::estimation<QP> current, kalman::estimation<QP> next)
 {
-  fmt::print("{:2} | {:7%.4Q} | {:10%.3Q %q} | {:>18} | {:>18}\n", iteration, gain, measured.relative(), current, next);
+  fmt::print("{:2} | {:7%.3Q} | {:10%.3Q %q} | {:>16.2} | {:>16.2}\n", iteration, gain, measured.relative(), current, next);
 }
 
 int main()