Fix a bug in aer_apply_measure in libaer and enable libaer build in…

… Mac (#1860)

* support all platform for libaer. fix a bug in aer_apply_measure in libaer

* build libaer only in Linux and Darwin

CMakeLists.txt

@@ -452,8 +452,7 @@ else() # Standalone build
 
 	install(TARGETS qasm_simulator DESTINATION bin)
 
-	# build libaer.so (currently, Linux on x86 is supportted)
-	if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
+	if (CMAKE_SYSTEM_NAME STREQUAL "Linux" OR CMAKE_SYSTEM_NAME STREQUAL "Darwin")
 		set(AER_RUNTIME_SOURCE "${PROJECT_SOURCE_DIR}/contrib/runtime/aer_runtime.cpp")
 		if(CUDA_FOUND AND AER_THRUST_BACKEND STREQUAL "CUDA")
 			build_cuda(aer ${AER_RUNTIME_SOURCE} FALSE)

contrib/runtime/aer_runtime.cpp

@@ -13,6 +13,7 @@
  */
 #include "controllers/state_controller.hpp"
 #include <cmath>
+#include <stdio.h>
 
 // initialize and return state
 extern "C" {
@@ -51,8 +52,7 @@ uint_t aer_allocate_qubits(void *handler, uint_t num_qubits) {
 // measure qubits
 uint_t aer_apply_measure(void *handler, uint_t *qubits_, size_t num_qubits) {
   AER::AerState *state = reinterpret_cast<AER::AerState *>(handler);
-  std::vector<uint_t> qubits;
-  qubits.insert(qubits.end(), &(qubits_[0]), &(qubits[num_qubits - 1]));
+  std::vector<uint_t> qubits(qubits_, qubits_ + num_qubits);
   return state->apply_measure(qubits);
 };