# Tests the Rust standard library BTreeMap.

# Get and range returns nothing for an empty map.
get foo
range
---
get → None

# Inserting keys out of order will return them in order. Silence the insert
# output with ().
(insert b=2 a=1 c=3)
range
---
a=1
b=2
c=3

# Getting a key returns its value.
get b
---
get → Some("2")

# Bounded scans, where the end is exclusive.
range b
---
b=2
c=3

range a c
---
a=1
b=2

# An end bound less than the start bound panics. Expect the failure with !.
!range b a
---
Panic: range start is greater than range end in BTreeMap

# Replacing a key updates the value and returns the old one.
insert b=foo
get b
---
insert → Some("2")
get → Some("foo")