#define SYNTHESIZE_SINGLETON_FOR_CLASS(classname)           \
    static classname *shared##classname = nil;              \
                                                            \
+ (classname *)shared##classname{                           \
    @synchronized(self){                                    \
        if (shared##classname == nil){                      \
            shared##classname = [[self alloc] init];        \
        }                                                   \
    }                                                       \
                                                            \
    return shared##classname;                               \
}                                                           \
                                                            \
+ (id)allocWithZone:(NSZone *)zone{                         \
    @synchronized(self){                                    \
        if (shared##classname == nil){                      \
            shared##classname = [super allocWithZone:zone]; \
            return shared##classname;                       \
        }                                                   \
    }                                                       \
                                                            \
    return nil;                                             \
}                                                           \
                                                            \
- (id)copyWithZone:(NSZone *)zone{                          \
    return self;                                            \
}

//定义
@interface CodecNSObject : NSObject
+(instancetype)codecToInstance:(NSDictionary*)dic;
@end

@implementation CodecNSObject
//实现

+(instancetype)codecToInstance:(NSDictionary*)dic
{
    return [self.class objectWithKeyValues:[dic copy]];
}
@end

rapidjson:https://code.google.com/p/rapidjson/

这个工具依赖于：premake4，需要单独下载，它的说明里面有。

编译工作比较麻烦，碰到错误：

fatal error: 'tr1/tuple' file not found

的时候，给make 加个参数:

make -f test.make CPPFLAGS=-DGTEST_USE_OWN_TR1_TUPLE=1 
这个工具太折腾，建议去www.google.com.im 搜索json C++ class generator


有个朋友问我windows的REST SDK如何自动分析json，我着了一下，这个链接还算可以，追加到文章里来：