exclude other types from freestanding

include/emio/buffer.hpp

@@ -311,10 +311,12 @@ struct get_value_type<std::back_insert_iterator<Container>> {
   using type = typename Container::value_type;
 };
 
+#if __STDC_HOSTED__
 template <typename Char, typename Traits>
 struct get_value_type<std::ostreambuf_iterator<Char, Traits>> {
   using type = Char;
 };
+#endif
 
 template <typename T>
 using get_value_type_t = typename get_value_type<T>::type;

include/emio/formatter.hpp

@@ -299,9 +299,11 @@ constexpr const void* ptr(const std::unique_ptr<T, Deleter>& p) {
   return p.get();
 }
 
+#if __STDC_HOSTED__
 template <typename T>
 const void* ptr(const std::shared_ptr<T>& p) {
   return p.get();
 }
+#endif
 
 }  // namespace emio

include/emio/result.hpp

@@ -9,7 +9,9 @@
 #include <concepts>
 #include <cstdint>
 #include <optional>
-#include <stdexcept>
+#if __STDC_HOSTED__
+#  include <stdexcept>
+#endif
 #include <type_traits>
 
 #include "detail/predef.hpp"
@@ -82,14 +84,32 @@ inline constexpr struct {
  * - "no value" -> a value should be accessed but result<T> held an error
  * - "no error" -> a error should be accessed but result<T> held an value
  */
+#if __STDC_HOSTED__
 class bad_result_access : public std::logic_error {
  public:
   /**
    * Constructs the bad result access from a message.
    * @param msg The exception message.
    */
-  explicit bad_result_access(const std::string_view& msg) : logic_error{msg.data()} {}
+  explicit bad_result_access(const std::string_view& msg) : logic_error{std::string{msg}} {}
 };
+#else
+class bad_result_access : public std::exception {
+ public:
+  /**
+   * Constructs the bad result access from a message.
+   * @param msg The exception message.
+   */
+  explicit bad_result_access(const std::string_view& msg) : msg_{msg} {}
+
+  [[nodiscard]] const char* what() const noexcept override {
+    return msg_.data();
+  }
+
+ private:
+  std::string_view msg_;
+};
+#endif
 
 namespace detail {
 

include/emio/std.hpp

@@ -7,7 +7,9 @@
 #pragma once
 
 #include <exception>
-#include <filesystem>
+#if __STDC_HOSTED__
+#  include <filesystem>
+#endif
 #include <optional>
 #include <variant>
 
@@ -58,6 +60,7 @@ class formatter<T> : public formatter<std::string_view> {
   }
 };
 
+#if __STDC_HOSTED__
 /**
  * Formatter for std::filesystem::path.
  */
@@ -68,6 +71,7 @@ class formatter<std::filesystem::path> : public formatter<std::string_view> {
     return formatter<std::string_view>::format(out, arg.native());
   }
 };
+#endif
 
 /**
  * Formatter for std::monostate.