Docstring duplication and edits

stan/math/prim/fun/acosh.hpp

@@ -82,6 +82,16 @@ inline auto acosh(const T& x) {
   return apply_scalar_unary<acosh_fun, T>::apply(x);
 }
 
+/**
+ * Return the elementwise application of <code>acosh()</code> to
+ * specified argument container.  The return type promotes the
+ * underlying scalar argument type to double if it is an integer,
+ * and otherwise is the argument type.
+ *
+ * @tparam T type of container
+ * @param x container
+ * @return Elementwise acosh of members of container.
+ */
 template <typename Container,
           require_container_bt<std::is_arithmetic, Container>* = nullptr>
 inline auto acosh(const Container& x) {

stan/math/prim/fun/asinh.hpp

@@ -70,6 +70,14 @@ inline auto asinh(const T& x) {
   return apply_scalar_unary<asinh_fun, T>::apply(x);
 }
 
+/**
+ * Returns the elementwise `asinh()` of the input,
+ * which may be a scalar or any Stan container of numeric scalars.
+ *
+ * @tparam T type of container
+ * @param x container
+ * @return Inverse hyperbolic sine of each value in the container.
+ */
 template <typename Container,
           require_container_bt<std::is_arithmetic, Container>* = nullptr>
 inline auto asinh(const Container& x) {

stan/math/prim/fun/atanh.hpp

@@ -81,6 +81,16 @@ inline auto atanh(const T& x) {
   return apply_scalar_unary<atanh_fun, T>::apply(x);
 }
 
+/**
+ * Return the elementwise application of <code>atanh()</code> to
+ * specified argument container.  The return type promotes the
+ * underlying scalar argument type to double if it is an integer,
+ * and otherwise is the argument type.
+ *
+ * @tparam T type of container
+ * @param x container
+ * @return Elementwise atanh of members of container.
+ */
 template <typename Container,
           require_container_bt<std::is_arithmetic, Container>* = nullptr>
 inline auto atanh(const Container& x) {

stan/math/prim/fun/inv_cloglog.hpp

@@ -50,6 +50,19 @@ inline auto inv_cloglog(const T x) {
   return 1. - std::exp(-std::exp(x));
 }
 
+/**
+ * The inverse complementary log-log function.
+ *
+ * The function is defined by
+ *
+ * <code>inv_cloglog(x) = 1 - exp(-exp(x))</code>.
+ *
+ * This function can be used to implement the inverse link
+ * function for complementary-log-log regression.
+ *
+ * @param x Argument.
+ * @return Inverse complementary log-log of the argument.
+ */
 template <typename T, require_complex_t<T>* = nullptr>
 inline auto inv_cloglog(const T& x) {
   return 1. - exp(-exp(x));

stan/math/prim/meta/is_container.hpp

@@ -91,12 +91,15 @@ template <template <class...> class TypeCheck, class... Check>
 using require_not_container_st
     = require_not_t<container_type_check_base<is_container, scalar_type_t,
                                               TypeCheck, Check...>>;
-/*! @} */
 
+/*! \brief Require type satisfies @ref is_container */
+/*! and holds a base type that satisfies @ref is_autodiff */
+/*! @tparam T the type to check */
 template <typename T>
 using require_ad_container_t
     = require_all_t<stan::math::disjunction<is_eigen<T>, is_std_vector<T>>,
                     is_autodiff<base_type_t<T>>>;
+/*! @} */
 
 }  // namespace stan
 

stan/math/prim/meta/is_real.hpp

@@ -16,7 +16,8 @@
 namespace stan {
 
 /**
- * Checks if decayed type is a var, fvar, or arithmetic
+ * Checks if decayed type is a var, fvar, or arithmetic. This
+ * is equivalent to @ref is_stan_scalar, except for excluding std::complex
  * @tparam The type to check
  * @ingroup type_trait
  */