feat formats: automatic serialization/deserialization based on Boost.PFR

universal/include/userver/formats/common/meta.hpp

@@ -32,9 +32,14 @@ template <typename Value, typename T>
 using HasConvert =
     decltype(Convert(std::declval<const Value&>(), parse::To<T>{}));
 
+template <typename Value, typename T>
+using HasTryParse =
+    decltype(TryParse(std::declval<const Value&>(), parse::To<T>{}));
+
 template <typename Value>
 using IsFormatValue = typename Value::ParseException;
 
+
 template <class Value, class T>
 constexpr inline bool kHasParse = meta::kIsDetected<HasParse, Value, T>;
 
@@ -44,6 +49,9 @@ constexpr inline bool kHasSerialize = meta::kIsDetected<HasSerialize, Value, T>;
 template <class Value, class T>
 constexpr inline bool kHasConvert = meta::kIsDetected<HasConvert, Value, T>;
 
+template <class Value, class T>
+constexpr inline bool kHasTryParse = meta::kIsDetected<HasTryParse, Value, T>;
+
 }  // namespace impl
 
 /// Used in `Parse` overloads that are templated on `Value`, avoids clashing

universal/include/userver/formats/parse/try_parse.hpp

@@ -0,0 +1,61 @@
+#pragma once
+#include <type_traits>
+#include <string>
+#include <cstdint>
+#include <userver/formats/parse/to.hpp>
+#include <userver/utils/meta.hpp>
+#include <userver/utils/impl/type_list.hpp>
+#include <userver/formats/common/meta.hpp>
+
+USERVER_NAMESPACE_BEGIN
+
+namespace formats::parse {
+
+namespace impl {
+
+template <typename T, typename Value>
+constexpr inline bool Is(Value&& value) {
+  if constexpr(std::is_convertible_v<T, std::int64_t>) {
+    return value.IsInt();
+  } else if constexpr(std::is_convertible_v<T, std::string>) {
+    return value.IsString();
+  } else if constexpr(requires {std::begin(std::declval<T>());}) {
+    return value.IsArray();
+  } else if constexpr(std::is_convertible_v<bool, T>) {
+    return value.IsBool();
+  } else {
+    return value.IsObject();
+  }
+}
+
+inline constexpr utils::impl::TypeList<bool, std::int64_t, std::uint64_t, double, std::string> kBaseTypes;
+
+
+} // namespace impl
+
+
+template <typename T, typename Value>
+constexpr inline std::enable_if_t<utils::impl::AnyOf(utils::impl::IsConvertableCarried<T>(), impl::kBaseTypes), std::optional<T>>
+TryParse(Value&& value, userver::formats::parse::To<T>) {
+  if(!impl::Is<T>(value)) {
+    return std::nullopt;
+  }
+  auto obj = value.template As<std::optional<T>>();
+  if(obj) {
+    return obj;
+  }
+  return std::nullopt;
+}
+
+template <typename T, typename Value>
+constexpr inline std::optional<std::optional<T>> TryParse(Value&& value, userver::formats::parse::To<std::optional<T>>) {
+  auto object = TryParse(std::forward<Value>(value), userver::formats::parse::To<T>{});
+  if(object) {
+    return object;
+  }
+  return std::nullopt;
+}
+
+} // namespace formats::parse
+
+USERVER_NAMESPACE_END

universal/include/userver/formats/universal/common_checks.hpp

@@ -0,0 +1,139 @@
+
+#pragma once
+#include <userver/formats/universal/universal.hpp>
+#include <userver/utils/regex.hpp>
+#include <fmt/format.h>
+#include <map>
+
+USERVER_NAMESPACE_BEGIN
+namespace formats::universal::impl {
+
+
+template <auto Value>
+struct Min {
+  static constexpr auto kValue = Value;
+};
+
+template <auto Value>
+struct Max {
+  static constexpr auto kValue = Value;
+};
+
+template <auto Value>
+struct Default {
+  static constexpr auto kValue = Value;
+};
+
+template <utils::ConstexprString Regex>
+struct Pattern {
+  static constexpr auto kValue = Regex;
+};
+
+struct Additional {};
+
+template <typename Field, auto Value>
+constexpr inline std::enable_if_t<!meta::kIsOptional<Field>, bool>
+Check(const Field& field, Max<Value>) noexcept {
+  return Value >= field;
+};
+
+template <typename Field, auto Value>
+constexpr inline std::enable_if_t<!meta::kIsOptional<Field>, bool>
+Check(const Field& field, Min<Value>) noexcept {
+  return field >= Value;
+};
+
+template <typename Field, auto Value>
+constexpr inline auto Check(const Field&, Default<Value>) noexcept {
+  return true;
+};
+
+template <utils::ConstexprString Regex>
+static const userver::utils::regex kRegex(Regex);
+
+template <utils::ConstexprString Regex>
+constexpr inline auto Check(const std::string& field, Pattern<Regex>) noexcept {
+  return utils::regex_match(field, kRegex<Regex>);
+};
+
+template <typename Field, auto Value>
+constexpr inline auto Check(const std::optional<Field>&, Default<Value>) noexcept {
+  return true;
+};
+
+template <typename Field>
+constexpr inline
+std::enable_if_t<!meta::kIsOptional<Field>, bool>
+Check(const Field&, Additional) noexcept {
+  return true;
+};
+
+template <typename Key, auto Value>
+constexpr inline auto Check(const std::vector<Key>& field, Max<Value>) noexcept {
+  return Value >= field.size();
+};
+
+template <typename Key, typename Tp, auto Value>
+constexpr inline auto Check(const std::map<Key, Tp>& field, Max<Value>) noexcept {
+  return Value >= field.size();
+};
+
+template <typename Key, typename Tp, auto Value>
+constexpr inline auto Check(const std::unordered_map<Key, Tp>& field, Max<Value>) noexcept {
+  return Value >= field.size();
+};
+
+template <typename Field, typename CheckT>
+constexpr inline bool Check(const std::optional<Field>& field, CheckT check) noexcept {
+  if(field.has_value()) {
+    return Check(*field, check);
+  };
+  return true;
+};
+
+template <typename T, auto I, typename Key, typename Value, auto Maximum>
+constexpr inline auto ErrorMessage(const std::unordered_map<Key, Value>& field, Max<Maximum>) {
+  return fmt::format("Error with field {0} Map size: {1} Maximum Size: {2}", boost::pfr::get_name<I, T>(), field.size(), Maximum);
+};
+
+template <typename T, auto I, typename Field, template <auto> typename Check, auto Value>
+constexpr inline auto ErrorMessage(const Field& field, Check<Value>) {
+  return fmt::format("Error with field {0} Field value: {1} Check Value: {2}", boost::pfr::get_name<I, T>(), field, Value);
+};
+
+
+template <typename T, auto I, typename Value, typename Check>
+constexpr inline auto ErrorMessage(const std::unordered_map<std::string, Value>&, Additional) {
+  return "Error";
+};
+
+template <typename T, auto I, typename Field, typename Check>
+constexpr inline auto ErrorMessage(const Field&, Check) {
+  return "Error";
+};
+
+template <typename T, auto I, typename Field, template <auto> typename Check, auto Value>
+constexpr inline auto ErrorMessage(const std::optional<Field>& field, Check<Value> check) {
+  return ErrorMessage<T, I>(*field, check);
+};
+
+} // namespace formats::universal::impl
+namespace formats::universal {
+template <auto Value>
+inline constexpr impl::Min<Value> Min;
+
+template <auto Value>
+inline constexpr impl::Max<Value> Max;
+
+template <auto Value>
+inline constexpr impl::Default<Value> Default;
+
+inline constexpr impl::Additional Additional;
+
+template <utils::ConstexprString Regex>
+inline constexpr impl::Pattern<Regex> Pattern;
+
+} // namespace formats::universal
+
+USERVER_NAMESPACE_END
+