View Compilation Error

0_0_4791642_22733.cpp:18: error: two or more data types in declaration of `mmax'
0_0_4791642_22733.cpp: In function `l mmax(double, double)':
0_0_4791642_22733.cpp:18: error: return type `struct l' is incomplete
0_0_4791642_22733.cpp:19: error: conversion from `double' to non-scalar type `l' requested