Doxygen documentation added

src/include/units/bits/external/fixed_string.h

@@ -27,6 +27,12 @@
 
 namespace units {
 
+/**
+ * @brief A compile-time fixed string
+ * 
+ * @tparam CharT Character type to be used by the string
+ * @tparam N The size of the string
+ */
 template<typename CharT, std::size_t N>
 struct basic_fixed_string {
   CharT data_[N + 1] = {};

src/include/units/concepts.h

@@ -189,6 +189,14 @@ struct dimension_unit_impl<D> {
 
 } // namespace detail
 
+/**
+ * @brief Returns a 'default' unit of the dimension
+ * 
+ * Depending on the dimension type it returns a base unit (for base dimensions)
+ * or a coherent unit (in case of derived dimensions).
+ * 
+ * @tparam D Dimension type to get the unit from.
+ */
 template<Dimension D>
 using dimension_unit = detail::dimension_unit_impl<D>::type;
 

src/include/units/math.h

@@ -29,13 +29,15 @@
 
 namespace units {
 
-template<std::intmax_t N, typename D, typename U, typename Rep>
-  requires(N == 0)
-inline Rep pow(const quantity<D, U, Rep>&) noexcept
-{
-  return 1;
-}
-
+/**
+ * @brief Computes the value of a quantity raised to the power `N`
+ * 
+ * Both the quantity value and its dimension are the base of the operation.
+ * 
+ * @tparam N Exponent
+ * @param q Quantity being the base of the operation
+ * @return Quantity The result of computation 
+ */
 template<std::intmax_t N, typename D, typename U, typename Rep>
   requires(N != 0)
 inline Quantity AUTO pow(const quantity<D, U, Rep>& q) noexcept
@@ -47,6 +49,26 @@ inline Quantity AUTO pow(const quantity<D, U, Rep>& q) noexcept
   return quantity<dim, unit, Rep>(static_cast<Rep>(std::pow(q.count(), N)));
 }
 
+/**
+ * @brief OVerload that always returns 1 for N == 0
+ * 
+ * @return Rep A scalar value of @c 1. 
+ */
+template<std::intmax_t N, typename D, typename U, typename Rep>
+  requires(N == 0)
+inline Rep pow(const quantity<D, U, Rep>&) noexcept
+{
+  return 1;
+}
+
+/**
+ * @brief Computes the square root of a quantity
+ * 
+ * Both the quantity value and its dimension are the base of the operation.
+ * 
+ * @param q Quantity being the base of the operation
+ * @return Quantity The result of computation 
+ */
 template<typename D, typename U, typename Rep>
 inline Quantity AUTO sqrt(const quantity<D, U, Rep>& q) noexcept
   requires requires { std::sqrt(q.count()); }
@@ -57,6 +79,12 @@ inline Quantity AUTO sqrt(const quantity<D, U, Rep>& q) noexcept
   return quantity<dim, unit, Rep>(static_cast<Rep>(std::sqrt(q.count())));
 }
 
+/**
+ * @brief Computes the absolute value of a quantity
+ * 
+ * @param q Quantity being the base of the operation
+ * @return Quantity The absolute value of a provided quantity
+ */
 template<typename D, typename U, typename Rep>
 constexpr Quantity AUTO abs(const quantity<D, U, Rep>& q) noexcept
   requires requires { std::abs(q.count()); }
@@ -64,6 +92,14 @@ constexpr Quantity AUTO abs(const quantity<D, U, Rep>& q) noexcept
   return quantity<D, U, Rep>(std::abs(q.count()));
 }
 
+/**
+ * @brief Returns the epsilon of the quantity
+ * 
+ * The returned value is defined by a <tt>std::numeric_limits<typename Q::rep>::epsilon()</tt>.
+ * 
+ * @tparam Q Quantity type being the base of the operation
+ * @return Quantity The epsilon value for quantity's representation type
+ */
 template<Quantity Q>
   requires requires { std::numeric_limits<typename Q::rep>::epsilon(); }
 constexpr Quantity AUTO epsilon() noexcept

src/include/units/ratio.h

@@ -33,6 +33,16 @@
 
 namespace units {
 
+/**
+ * @brief Provides compile-time rational arithmetic support.
+ * 
+ * This class is really similar to @c std::ratio but gets an additional `Exp`
+ * template parameter.
+ * 
+ * @tparam Num Numerator
+ * @tparam Den Denominator (default @c 1)
+ * @tparam Exp Exponent (default @c 0)
+ */
 template<std::intmax_t Num, std::intmax_t Den = 1, std::intmax_t Exp = 0>
   requires(Den != 0)
 struct ratio {

src/include/units/symbol_text.h

@@ -18,8 +18,20 @@ constexpr void validate_ascii_string([[maybe_unused]] const char (&s)[P + 1]) no
 #endif
 }
 
-}
+}  // namespace detail
 
+
+/**
+ * @brief A symbol text representation
+ * 
+ * This class template is responsible for definition and handling of a symbol text
+ * representation. In the libary it is used to define symbols of units and prefixes.
+ * Each symbol can have two versions: Unicode and ASCI-only.
+ * 
+ * @tparam StandardCharT Character type to be used for a Unicode representation
+ * @tparam N The size of a Unicode symbol
+ * @tparam M The size of the ASCII-only symbol
+ */
 template<typename StandardCharT, std::size_t N, std::size_t M>
 struct basic_symbol_text {
   basic_fixed_string<StandardCharT, N> standard_;