/// <summary>
/// Returns an object of the specified type and whose value is equivalent to the specified object.
/// </summary>
/// <param name="value">The object to convert the underlying type.</param>
/// <param name="conversionType">The <see cref="Type"/> of object to return.</param>
/// <param name="provider">An object that supplies culture-specific formatting information.</param>
/// <returns>An object whose type is <paramref name="conversionType"/> and whose value is equivalent to <paramref name="value"/>.</returns>
/// <remarks>What differs from the <see cref="Convert.ChangeType(object,System.Type)"/> is, that this converter supports generics and enums. Failover uses <see cref="TypeDescriptor"/>.</remarks>
public static object ChangeType(object value, Type conversionType, IFormatProvider provider)
{
Validator.ThrowIfNull(conversionType, nameof(conversionType));
if (value == null)
{
return(null);
}
try
{
bool isEnum = conversionType.GetTypeInfo().IsEnum;
bool isNullable = TypeUtility.IsNullable(conversionType);
return(Convert.ChangeType(isEnum ? Enum.Parse(conversionType, value.ToString()) : value, isNullable ? Nullable.GetUnderlyingType(conversionType) : conversionType, provider));
}
catch (Exception first)
{
try
{
return(TypeDescriptor.GetConverter(conversionType).ConvertFrom(value));
}
catch (Exception second)
{
throw new AggregateException(first, second);
}
}
}
/// <summary>
/// Determines whether the specified source is a nullable <see cref="ValueType"/>.
/// </summary>
/// <typeparam name="T">The type of the <paramref name="source"/> of <typeparamref name="T"/>.</typeparam>
/// <param name="source">The source type to check for nullable <see cref="ValueType"/>.</param>
/// <returns>
/// <c>true</c> if the specified source is nullable; otherwise, <c>false</c>.
/// </returns>
public static bool IsNullable<T>(this T source) { return TypeUtility.IsNullable(source); }
/// <summary>
/// Determines whether the specified source is a nullable <see cref="ValueType"/>.
/// </summary>
/// <typeparam name="T">The type of the <paramref name="source"/> of <typeparamref name="T"/>.</typeparam>
/// <param name="source">The source type to check for nullable <see cref="ValueType"/>.</param>
/// <returns>
/// <c>true</c> if the specified source is nullable; otherwise, <c>false</c>.
/// </returns>
public static bool IsNullable<T>(this T? source) where T : struct { return TypeUtility.IsNullable(source); }
/// <summary>
/// Determines whether the specified source is a nullable <see cref="ValueType"/>.
/// </summary>
/// <param name="source">The source type to check for nullable <see cref="ValueType"/>.</param>
/// <returns>
/// <c>true</c> if the specified source is nullable; otherwise, <c>false</c>.
/// </returns>
public static bool IsNullable(this Type source)
{
return(TypeUtility.IsNullable(source));
}
