C++ Decompress a gzip array of bytes

Here is the complete situation: I'm working on a map reader for .tmx files, from tiled. Most times the tiles are saved in a base64 string, which contains an array of bytes compressed by gzip. Right now I can read the array of compressed bytes, but I have no idea how to decompress it. I read some docs about zlib and boost, but both were about file streams and very complicated...

I'm very new to the data compression area, so if anyone knows a kinda solution or some helpful documentation I would really apreciate.