fix error with gcc on CI: missing explicit type

tests/test_determinist.cpp

@@ -185,8 +185,8 @@ TEST(DeterministTests, TestMaskingConditions)
     // conditions on streamflow values _________________________________________
 
     // compute scores using masking conditions on streamflow to subset whole record
-    xt::xtensor<std::array<char, 32>, 1> q_conditions ={
-            {"q_obs{<2000,>3000}"}
+    xt::xtensor<std::array<char, 32>, 1> q_conditions = {
+            std::array<char, 32> {"q_obs{<2000,>3000}"}
     };
 
     std::vector<xt::xarray<double>> metrics_q_conditioned =
@@ -217,7 +217,7 @@ TEST(DeterministTests, TestMaskingConditions)
 
     // compute scores using masking conditions on streamflow to subset whole record
     xt::xtensor<std::array<char, 32>, 1> q_conditions_ ={
-            {"q_obs{>=mean}"}
+            std::array<char, 32> {"q_obs{>=mean}"}
     };
 
     double mean = xt::mean(observed, {1})();
@@ -250,7 +250,7 @@ TEST(DeterministTests, TestMaskingConditions)
 
     // compute scores using masking conditions on time indices to subset whole record
     xt::xtensor<std::array<char, 32>, 1> t_conditions = {
-            {"t{0,1,2,3,4,5:97,97,98,99}"}
+            std::array<char, 32> {"t{0,1,2,3,4,5:97,97,98,99}"}
     };
 
     std::vector<xt::xarray<double>> metrics_t_conditioned =

tests/test_probabilist.cpp

@@ -201,7 +201,7 @@ TEST(ProbabilistTests, TestMaskingConditions)
 
     // compute scores using masking conditions on streamflow to subset whole record
     xt::xtensor<std::array<char, 32>, 2> q_conditions = {
-            {{"q_obs{<2000,>3000}"}}
+            {std::array<char, 32> {"q_obs{<2000,>3000}"}}
     };
 
     std::vector<xt::xarray<double>> metrics_q_conditioned =
@@ -234,7 +234,7 @@ TEST(ProbabilistTests, TestMaskingConditions)
 
     // compute scores using masking conditions on streamflow to subset whole record
     xt::xtensor<std::array<char, 32>, 2> q_conditions_ = {
-            {{"q_prd_mean{>=median}"}}
+            {std::array<char, 32> {"q_prd_mean{>=median}"}}
     };
 
     auto q_prd_mean = xt::mean(predicted, {0}, xt::keep_dims);
@@ -270,7 +270,7 @@ TEST(ProbabilistTests, TestMaskingConditions)
 
     // compute scores using masking conditions on time indices to subset whole record
     xt::xtensor<std::array<char, 32>, 2> t_conditions = {
-            {{"t{0,1,2,3,4,5:97,97,98,99}"}}
+            {std::array<char, 32> {"t{0,1,2,3,4,5:97,97,98,99}"}}
     };
 
     std::vector<xt::xarray<double>> metrics_t_conditioned =