@Override
    public void registerConverter(ConfigurationConverter converter) {
        delegate.registerConverter(converter);
    }

    @Override
    public ConfigurationConverter lookupConverterForType(Class<?> type) throws ComponentConfigurationException {
        ConfigurationConverter converter = delegate.lookupConverterForType(type);
        return converter.getClass().equals(ObjectWithFieldsConverter.class)

Então, mesmo com o código acima que não usa Pydantic explicitamente, o FastAPI está usando Pydantic para converter essas dataclasses padrão para a versão do Pydantic.

E claro, ele suporta o mesmo:

* validação de dados
* serialização de dados
* documentação de dados, etc.

import org.codehaus.plexus.component.configurator.converters.AbstractConfigurationConverter;
import org.codehaus.plexus.component.configurator.converters.basic.AbstractBasicConverter;
import org.codehaus.plexus.component.configurator.converters.composite.ObjectWithFieldsConverter;
import org.codehaus.plexus.component.configurator.converters.lookup.ConverterLookup;

/// danger | Perigo

Isso é um recurso "avançado".

Se você for um iniciante em **FastAPI** você deve considerar pular essa seção.

///

## Casos de Uso

Alguns casos de uso incluem:

* Converter requisições não-JSON para JSON (por exemplo, <a href="https://msgpack.org/index.html" class="external-link" target="_blank">`msgpack`</a>).
* Descomprimir corpos de requisição comprimidos com gzip.

    return b1 << 24 | (b2 & 0xFF) << 16 | (b3 & 0xFF) << 8 | (b4 & 0xFF);
  }

  private static final class IntConverter extends Converter<String, Integer>
      implements Serializable {
    static final Converter<String, Integer> INSTANCE = new IntConverter();

    @Override
    protected Integer doForward(String value) {
      return Integer.decode(value);
    }

conscrypt-android = { module = "org.conscrypt:conscrypt-android", version.ref = "org-conscrypt" }
conscrypt-openjdk = { module = "org.conscrypt:conscrypt-openjdk-uber", version.ref = "org-conscrypt" }
converter-moshi = { module = "com.squareup.retrofit2:converter-moshi", version.ref = "retrofit" }
eclipseOsgi = "org.eclipse.platform:org.eclipse.osgi:3.21.0"
findbugs-jsr305 = "com.google.code.findbugs:jsr305:3.0.2"

    } else if (accum == Long.MIN_VALUE) {
      return null;
    } else {
      return -accum;
    }
  }

  private static final class LongConverter extends Converter<String, Long> implements Serializable {
    static final Converter<String, Long> INSTANCE = new LongConverter();

    @Override
    protected Long doForward(String value) {
      return Long.decode(value);
    }

    @Override

import java.util.Map;
import java.util.TimeZone;
import java.util.function.Consumer;

import org.apache.lucene.search.TotalHits;
import org.codelibs.core.beans.BeanDesc;
import org.codelibs.core.beans.Converter;
import org.codelibs.core.beans.PropertyDesc;
import org.codelibs.core.beans.factory.BeanDescFactory;
import org.codelibs.core.beans.util.BeanUtil;
import org.codelibs.core.io.FileUtil;

        "the total number of elements (%s) in the arrays must fit in an int",
        result);
    return (int) result;
  }

  private static final class DoubleConverter extends Converter<String, Double>
      implements Serializable {
    static final Converter<String, Double> INSTANCE = new DoubleConverter();

    @Override
    protected Double doForward(String value) {
      return Double.valueOf(value);
    }

                    final OpenSearchAccessResult accessResult = BeanUtil.copyMapToNewBean(source, OpenSearchAccessResult.class, option -> {
                        option.converter(new EsTimestampConverter(), timestampFields).excludeWhitespace();
                        option.exclude(OpenSearchAccessResult.ACCESS_RESULT_DATA);
                    });
                    @SuppressWarnings("unchecked")