From 29852fbb3de95bf60eff4be316df09c55d07313f Mon Sep 17 00:00:00 2001
From: Yang Keao <keao.yang@yahoo.com>
Date: Tue, 15 Dec 2020 17:59:52 +0800
Subject: [PATCH] support stable rust

Signed-off-by: Yang Keao <keao.yang@yahoo.com>
---
 Cargo.toml | 3 ++-
 src/lib.rs | 7 ++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 65be5ce7..d4c521d8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,6 +14,7 @@ default = ["cpp"]
 flamegraph = ["inferno"]
 protobuf = ["prost", "prost-derive", "prost-build"]
 cpp = ["symbolic-demangle/cpp"]
+heap = []
 
 [dependencies]
 backtrace = "0.3"
@@ -55,7 +56,7 @@ required-features = ["flamegraph"]
 
 [[example]]
 name = "heap_profiler"
-required-features = ["protobuf", "flamegraph"]
+required-features = ["protobuf", "flamegraph", "heap"]
 
 [[bench]]
 name = "collector"
diff --git a/src/lib.rs b/src/lib.rs
index f1317065..115b0ffe 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -21,7 +21,7 @@
 //!};
 //! ```
 
-#![feature(const_fn)]
+#![cfg_attr(feature = "heap", feature(const_fn))]
 
 /// Define the MAX supported stack depth. TODO: make this variable mutable.
 pub const MAX_DEPTH: usize = 32;
@@ -32,7 +32,9 @@ pub const MAX_THREAD_NAME: usize = 16;
 mod collector;
 mod error;
 mod frames;
+#[cfg(feature = "heap")]
 mod heap_profiler;
+
 mod profiler;
 mod report;
 mod timer;
@@ -40,7 +42,10 @@ mod timer;
 pub use self::collector::{Collector, StackHashCounter};
 pub use self::error::{Error, Result};
 pub use self::frames::{Frames, Symbol};
+
+#[cfg(feature = "heap")]
 pub use self::heap_profiler::{AllocRecorder, HeapProfilerGuard};
+
 pub use self::profiler::ProfilerGuard;
 pub use self::report::{Report, ReportBuilder};