Added an example for generating keys using OsRng

.travis.yml

@@ -36,6 +36,7 @@ script:
   - cargo test --verbose
   - cargo build --verbose --release
   - cargo test --verbose --release
+  - cargo run --example generate_keys --features=rand
   - if [ ${TRAVIS_RUST_VERSION} == "stable" ]; then cargo doc --verbose --features="rand,serde,recovery,endomorphism"; fi
   - if [ ${TRAVIS_RUST_VERSION} == "nightly" ]; then cargo test --verbose --benches --features=unstable; fi
   - if [ ${TRAVIS_RUST_VERSION} == "stable" -a "$TRAVIS_OS_NAME" = "linux" ]; then 

Cargo.toml

@@ -13,6 +13,7 @@ keywords = [ "crypto", "ECDSA", "secp256k1", "libsecp256k1", "bitcoin" ]
 readme = "README.md"
 build = "build.rs"
 links = "secp256k1"
+autoexamples = false # Remove when edition 2018 https://github.com/rust-lang/cargo/issues/5330
 
 # Should make docs.rs show all functions, even those behind non-default features
 [package.metadata.docs.rs]
@@ -38,6 +39,7 @@ lowmemory = []
 rand = "0.6"
 rand_core = "0.4"
 serde_test = "1.0"
+bitcoin_hashes = "0.7"
 
 [dependencies.rand]
 version = "0.6"
@@ -48,3 +50,7 @@ default-features = false
 version = "1.0"
 optional = true
 default-features = false
+
+[[example]]
+name = "generate_keys"
+required-features = ["rand"]

examples/generate_keys.rs

@@ -0,0 +1,17 @@
+extern crate secp256k1;
+
+use secp256k1::rand::rngs::OsRng;
+use secp256k1::{PublicKey, Secp256k1, SecretKey};
+
+fn main() {
+    let secp = Secp256k1::new();
+    let mut rng = OsRng::new().unwrap();
+    // First option:
+    let (seckey, pubkey) = secp.generate_keypair(&mut rng);
+
+    assert_eq!(pubkey, PublicKey::from_secret_key(&secp, &seckey));
+
+    // Second option:
+    let seckey = SecretKey::new(&mut rng);
+    let _pubkey = PublicKey::from_secret_key(&secp, &seckey);
+}