How does one easily compose and broadcast?

For example,

```
x = randn(100,10)
mapslices(cumprod ∘ exp, x; dims=1)
```

fails because we need to broadcast `exp`

.

One workaround is to do the following

```
x = randn(100,10)
expdot(v) = exp.(v)
mapslices(cumprod ∘ expdot, x; dims=1)
```

Are there other, hopefully better, ways?