Merge pull request #1644 from bstatcomp/fix_returned_expressions

fix returned expressions
# Conflicts:
#	stan/math/prim/fun/log_softmax.hpp

Author: rok-cesnovar

stan/math/prim/fun/acos.hpp

@@ -45,7 +45,7 @@ inline auto acos(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto acos(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().acos().matrix();
+  return x.derived().array().acos().matrix().eval();
 }
 
 }  // namespace math

stan/math/prim/fun/asin.hpp

@@ -45,7 +45,7 @@ inline auto asin(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto asin(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().asin().matrix();
+  return x.derived().array().asin().matrix().eval();
 }
 
 }  // namespace math

stan/math/prim/fun/atan.hpp

@@ -45,7 +45,7 @@ inline typename apply_scalar_unary<atan_fun, T>::return_t atan(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto atan(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().atan().matrix();
+  return x.derived().array().atan().matrix().eval();
 }
 
 }  // namespace math

stan/math/prim/fun/ceil.hpp

@@ -45,7 +45,7 @@ inline auto ceil(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto ceil(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().ceil().matrix();
+  return x.derived().array().ceil().matrix().eval();
 }
 
 }  // namespace math

stan/math/prim/fun/cos.hpp

@@ -45,7 +45,7 @@ inline auto cos(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto cos(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().cos().matrix();
+  return x.derived().array().cos().matrix().eval();
 }
 
 }  // namespace math

stan/math/prim/fun/cosh.hpp

@@ -45,7 +45,7 @@ inline typename apply_scalar_unary<cosh_fun, T>::return_t cosh(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto cosh(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().cosh().matrix();
+  return x.derived().array().cosh().matrix().eval();
 }
 
 }  // namespace math

stan/math/prim/fun/exp.hpp

@@ -60,7 +60,7 @@ inline auto exp(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto exp(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().exp().matrix();
+  return x.derived().array().exp().matrix().eval();
 }
 
 }  // namespace math

stan/math/prim/fun/fabs.hpp

@@ -45,7 +45,7 @@ inline typename apply_scalar_unary<fabs_fun, T>::return_t fabs(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto fabs(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().abs().matrix();
+  return x.derived().array().abs().matrix().eval();
 }
 
 /**
@@ -57,7 +57,7 @@ inline auto fabs(const Eigen::MatrixBase<Derived>& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto fabs(const Eigen::ArrayBase<Derived>& x) {
-  return x.derived().abs();
+  return x.derived().abs().eval();
 }
 
 }  // namespace math

stan/math/prim/fun/floor.hpp

@@ -45,7 +45,7 @@ inline auto floor(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto floor(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().floor().matrix();
+  return x.derived().array().floor().matrix().eval();
 }
 
 }  // namespace math

stan/math/prim/fun/inv.hpp

@@ -45,7 +45,7 @@ inline auto inv(const T& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto inv(const Eigen::MatrixBase<Derived>& x) {
-  return x.derived().array().inverse().matrix();
+  return x.derived().array().inverse().matrix().eval();
 }
 
 /**
@@ -57,7 +57,7 @@ inline auto inv(const Eigen::MatrixBase<Derived>& x) {
 template <typename Derived,
           typename = require_eigen_vt<std::is_arithmetic, Derived>>
 inline auto inv(const Eigen::ArrayBase<Derived>& x) {
-  return x.derived().inverse();
+  return x.derived().inverse().eval();
 }
 
 }  // namespace math