In most times, const_cast is bad and break interface contract and

make the code unreadable and make the program unstable.

test=develop

paddle/fluid/operators/cudnn_lstm_op.cu.cc

@@ -300,9 +300,11 @@ class CudnnLSTMGPUKernel : public framework::OpKernel<T> {
     }
     CudnnRNNCache *cudnn_rnn_cache = nullptr;
     if (cache_var->IsInitialized()) {
+      // const_cast is usually bad.
       cudnn_rnn_cache = const_cast<framework::Variable *>(cache_var)
                             ->GetMutable<CudnnRNNCache>();
     } else {
+      // const_cast is usually bad.
       cudnn_rnn_cache = const_cast<framework::Variable *>(cache_var)
                             ->GetMutable<CudnnRNNCache>();
       std::random_device rnd;

paddle/scripts/paddle_build.sh

@@ -517,6 +517,18 @@ function assert_api_spec_approvals() {
           fi
       fi
     done
+
+    HAS_CONST_CAST=`git diff -U0 upstream/$BRANCH |grep const_cast`
+    if [ ${HAS_CONST_CAST} ] && [ "${GIT_PR_ID}" != "" ]; then
+        APPROVALS=`curl -H "Authorization: token ${GITHUB_API_TOKEN}" https://api.github.com/repos/PaddlePaddle/Paddle/pulls/${GIT_PR_ID}/reviews?per_page=10000 | \
+        python ${PADDLE_ROOT}/tools/check_pr_approval.py 2 7845005 2887803 728699 13348433`
+        echo "current pr ${GIT_PR_ID} got approvals: ${APPROVALS}"
+        if [ "${APPROVALS}" == "FALSE" ]; then
+            echo "You must have at least 2 approvals for the const_cast"
+        exit 1
+        fi
+    fi
+
 }