Wrapper for Objective-C type encodings

TypeEncoding.h

@import Foundation;

typedef NS_ENUM(unichar, EncodedType) {
    TypeChar              = 'c',
    TypeInt               = 'i',
    TypeShort             = 's',
    TypeLong              = 'l',  // note long encodes to q on 64 bit
    TypeLongLong          = 'q',
    TypeUnsignedChar      = 'C',
    TypeUnsignedInt       = 'I',
    TypeUnsignedShort     = 'S',
    TypeUnsignedLong      = 'L',
    TypeUnsignedLongLong  = 'Q',
    TypeFloat             = 'f',
    TypeDouble            = 'd',
    TypeBool              = 'B',  // note, BOOL encodes to c on 64 bit
    TypeVoid              = 'v',
    TypeCString           = '*',
    TypeObject            = '@',
    TypeClass             = '#',
    TypeSelector          = ':',
    TypeArray             = '[',
    TypeStruct            = '{',
    TypeUnion             = '(',
    TypeBitField          = 'b',
    TypePointer           = '^',
    TypeUnknown           = '?',
};

NS_ASSUME_NONNULL_BEGIN

@interface TypeEncoding : NSObject

@property (nonatomic, readonly) EncodedType type;

/// The raw type encoding
@property (nonatomic, readonly, copy) NSString *encoding;

/// Either an object, a Class type, or a block
@property (nonatomic, readonly) BOOL isObjectType;

/// Float or double
@property (nonatomic, readonly) BOOL isFloatType;

/// A signed or unsigned integer of any size
@property (nonatomic, readonly) BOOL isIntType;

/// The class of the object. Nil for anything except TypeObject.
@property (nonatomic, readonly, nullable) Class classType;

- (instancetype)initWithEncoding:(NSString *)encoding;

@end

NS_ASSUME_NONNULL_END

TypeEncoding.m

#import "TypeEncoding.h"

@implementation TypeEncoding

- (instancetype)initWithEncoding:(NSString *)encoding {
    self = [super init];
    if (self) {
        _encoding = [encoding copy];
        _type = [encoding characterAtIndex:0];

        static const unichar TypeConst = 'r';
        if (_type == TypeConst) {
            // const C strings are encoded as "r*" -- skip the leading 'r'
            _type = [encoding characterAtIndex:1];
        }
    }
    return self;
}

- (BOOL)isObjectType {
    return _type == TypeObject || _type == TypeClass;
}

- (BOOL)isFloatType {
    return _type == TypeFloat || _type == TypeDouble;
}

- (BOOL)isIntType {
    static const char *integralTypes = "cislqCISLQB";
    return strchr(integralTypes, _type) != NULL;
}

- (Class)classType {
    if (_type == TypeObject
        && [_encoding hasPrefix:@"@\""] && [_encoding hasSuffix:@"\""]) {
        NSRange range = NSMakeRange(2, _encoding.length - 3);
        NSString *classStr = [_encoding substringWithRange:range];
        return NSClassFromString(classStr) ?: NSObject.class;
    }
    return nil;
}

@end